>>725798814
It's honestly ironic because the highly unrealistic fictional anime mechs are substantially more realistic than the "realistic" chicken-walkers by merit of precisely what you said there.
>Faster than all fuck
>Protected by a particle energy barrier
If they take too many hits, they will literally be obliterated. In modern warfare, we're already seeing tanks be made totally obsolete through the use of long-ranged missiles and aircraft, and even mild things like temu drones are capable of flatlining a tank, its crew, and supporting infantry. If a mech was ever to be fielded in the modern era, it would honestly have to be something potent enough to justify using it instead of just another tomahawk missile, and nothing short of some barely-believable mechanical force of nature would be worth the budget that would be put into it.