It wouldn't, right now most people I play against don't even care about cover, they just rush in their LMG grens and rip everything apart, and late game this become even worse since most cover will be destroyed Grens just win every engagement, they need some reduction in their rec acc so cover don't transform them into matrix characters.
But Late game 80% of the time has light cover craters everywhere. I don't know what your talking about.
Also grens are very squishy unless vet 3, I'd rather use the glorious prosttruppen late game because of cost and how much durable prosttruppen are all together vs grens.
Also, you have to consider all units if doing something that affects all units. AssGrens, AssEngies, Pgrens, REs, Sappers, Sturmpios, Falls, Commandos, Pioneers, PPSH Cons, STG Volks, Thompson Rangers and Paras, Partysans, and Stormtoopers would all be heavily nerfed and be completely inferior to Units with LMGs in 90% of situations now.
And that's alot of infantry