>>720042420
>Tech level required to make this mechs: >>720036613
>Would render any mech completely obsolete
Put aside that you've chosen a silly example that's not even trying to be realistic
Improved tech level make so many more design obsolete that your doctrine change and you no longer see a problem in making robot/walker if it gives you an edge in any context.

I don't give a shit if plain warfare is done with battletank or artillery
If it turns out mecha become invaluable in fielding integrated anti-air anti-drone anti-shell systems along soldiers and you can't go fully unmanned because of jamming/hacking.