Legs can be protected to a point, and if pressure is a concern, use bigger feet.
But to get anywhere near the ratio of a conventional tank, the feet would have to be bigger than the rest of the MECH.
Why nature would evolve bipedal and multipedal designs is because they have their distinct advantages.
Sure, but don't forget that nature has to deal with other limitations than technology. No living organism can grow a free rotating wheel on it's body, because that wheel would have to be detached from the rest of the body to be able to turn more than 360°. Just like no fish can ever grow a screw propulsion like we use it for our ships.
So even though legs are the result of billions of years of evolution and wheels are only the result of mere human imagination, that doesn't neccessarily mean that legs have to be that superiour.
What is so special and if you will, genious about a tracked vehicle is that it in some way always carries around it's own road with it. That is an advantage with which even legs cannot compete that easily.
Offroad mobility is superior with legs, which combines both suspension and the propulsion mechanism in one package. A mech can move quite fast with its legs, and yet can provide a far more stable shooting platform than a tank at speed, which has to bounce up and down with the terrain. Legs are also more flexible. For example, if you ever played an FPS game, are you familiar with the technique called strafing? That means you're going sideways while shooting at the target.
Sure, but a tank can just turn by 90° and then drive into another direction while the turret with the gun still aims at the former direction. That is pretty much the same, isn't it?
I guess you will argue that a MECH would strafe much faster than a tank could change the direction. But you have to consider that what the MECHS do in those computer games is not physically accurate. Not even a human can run forward at full speed and then suddenly change the direction by 90° without stopping first. A very flat vehicle with a very low center of gravity can actually do that better than anything that is standing upright. So the fact that a real tank in the real world isn't "strafing" as fast as a MECH in a computer game, doesn't reflect physical laws and isn't a credible comparison.
Mobility, a mech can wade through deeper water than a tank can.
Did you ever see a MBT with a 5m air tube ("snorkel") attached to it? If a tank can wade through 6-7m deep water today, i'm pretty sure tanks in a future in which they have to compete with MECHS will be able to do that too. Especially if they'll be equiped with electrical populsion that doesn't require oxygene to run anymore.
An no matter whether in the open field, or in a swamp or in a soft, spongy river bed, a MECH would always have bigger problems with sinking into the ground than a tank would have, because of that inevitable worse ground pressure ratio.
Depending on size, I would think that mechs around the size depicted in the Heavy Gear franchise or in the anime show Votoms can do a better job traveling through tight roads and cities than tanks.
OK, sure, but that is another league so to say. Such small MECHS would rather compete with infantry and/or small military robots, than with tanks. A MECH of the same weight-, armour- and firepower-class as a tank wouldn't neccessary be any more mobile in an urban area than a tank. Where the MECH might be better in walking over small structures, the tank would be better in driving under bridges and through tunnels.
And a big MECH with the big feet it needs would have problems with stair-like uneven ground and might stumble like that big robot in the movie Robocop, where a tank would simply roll up or down.
To say "The MECHS will be so advanced and secure on their feed that they will not stumble." is very questinable too. Don't forget how many years of evolution were neccessary to create us with our legs. Our biological walking mechanism and the nervous system that is used to controll it are far more advanced than anything that could be build and still be called a machine. And still we stumble quite often, don't we? Even four legged animals stumble.
Another factor is that a future tank with an electrical propulsion might be very quiet and thus more "stealthy" than a MECH could ever be.
They can also travel through areas where no tank can, and one thing they can do is actually climb.
That again depends on the size and weight of the MECH. I doubt that there would be much oportunity to climb up things for a MECH that weights as much as a MBT. Not many buildings or natural walls are stable enough to allow something that weights 30 to 60 tons to climb up on it without tearing at least parts of it down, i guess.
If you want to reduce your frontal visibility, the mech can go into a prone position, like a solder trying to be a sniper. While it is up, its height provides a better vantage point for sensors, which can increase its range.
Maybe, but that would take time and if he has the time to go into a prone position, that wouldn't leave him better off than the tank is all the time. And the tank can actually move at maximum speed while always being in a prone position, if you will.
If the advantage of firing from a higher angle would outweight the disadvantage of being an easier target yourself, then modern tanks wouldn't become flater but higher. That development will surely even increase the more clever self guiding missles become. For a missle that guides itself to the target and performs a top attack on it, it does hardly matter whether it's launched from 2m above the ground or from 8m above the ground.
Mechs can be handy for lets say, building make shift bases on the spot. They are their own engineering and construction equipment.
OK, but it is very speculative to assume that something like that will be neccessary. As it looks today, the airlift-ability and all over mobility of armies will increase in the future, making temporary bases near the frontline less useful. Besides, there are tanks with pioneering equipment....
And to go back to nature...
When we look at nature we can see that all animals that rely on armour (like the turtle, the sea urchin, the lobster, the centipede and most bugs) have a flat, ducked body shape and a form that improves their ratio of body volume to surface. Because the smaller the surface, the more you can armour it without increasing the weight too much.
Considering that principle, the MECH really looks bad. You'd have to armour not just a relatively small structure but a lot of surface. The ratio of volume to weight would become ridiculous compared to a tank.
Of course they will have better, lighter armour in the future, but the principle remains. A tank using the same new super armour will still be way tougher and maybe even more agile due to the low center of gravity, than the MECH.
But if you reduce the MECHs armour drastically to gain mobility instead of protection, that makes it a competitor to the helicopter gunship. Another competition it cannot win, because it will never be as mobile and fast as the helicopter, just as it will never be as tough as the tank. So the MECH is a idea that is sitting between the chairs, so to say. And it will never make sense because the principles that cause it's inferiority to the two other systems are universal and cannot be changed by technological development, because every new technology that would be invented to make the MECH better, would also make the tank and/or the helicopter (or the antigravity flying saucer that might replace it some day) better.
