I love mecha, but the larger you are, the easier it is for things to find you. this is why tanks try to stay low to the ground.

and walking is a really inefficient mode of transit compared to wheels or treads. and keeping 50+ tons of mecha balanced on two legs while going up hill or on rough terrain would be quite a feat.

so no, barring tremendous advances in point defense (to counter drones and atgms), I don’t see it happening any time soon, and even then it’d have to be in response to some other pressure.