I think we're all being limited by an unrealistic expectation of what we expect from our Infantry, especially with respect to the vehicles we mount them in. Infantry don't do their jobs from the equivalent of the light tank, at least 99% of the time. They do it on their bellies, with grenades, rifles and bayonets.
Sure, the vehicles from which we engage the enemy need to be survivable, and having a gun on it is a bonus, but the main 'enabler' we need to properly close with and destroy the enemy is armour and artillery, and mortars and anti-armour weapons and machine guns and pioneers, and close air support.
A huge focus on making the Infantry 'Junior Zipper Heads' is probably not the answer.
A better all arms battlefield team, kind of like the Germans' Blitzkrieg showed us in WW2 (or the Allies' last 100 days in WW1) is probably more like what we need to get better at. The equivalent of a Sherman Tank (in height anyways, as we seem to have already exceeded the weight) is probably putting the emPHASIS on the wrong syllABLE.
My $0.02 worth.