Which is why "no armor" to "some armor" suddenly becomes non-negotiable, given shrapnel's lethal radius.
But maybe future armor looks more like minimal armor, maximum speed, and substantial EW countermeasures?
Tactical mobility is a bit overrated, it's not like you can outrun an ATGM. Though a system with better operational and strategic mobility would certainly be valuable. Modern tanks can't cross a lot of bridges due to weight constraints, and can only be air transported in the largest aircraft. For reference: the C-5 galaxy, one of the largest cargo planes in existence, can carry 2 abrams tanks; the more common C-17 can carry 1; while the C-130 can't carry any (it could transport roughly 28% of an abrams). If you could get a decent armored fighting vehicle down to 20-30 tons that opens up a lot of operational and strategic transport options.
specifically, the Abrams is getting real heavy these days with all the upgrades, to the extent that it's becoming an operational problem. They can't be towed by their recovery vehicle anymore. They're too heavy for their carrier trucks/trailers. They can't use landing craft or bailey bridges. A lot of constructed bridges in the expected area of operations can't support them.
https://www.defensedaily.com/80-ton-abrams-heavy-support-veh...
https://www.aspistrategist.org.au/australias-new-tanks-are-o...
And by definition, infantry must be out in the open as it advances; distinct from when it defends.
Consequently, the purpose of armored vehicles (tanks, APCs/IFVs, SPGs) is not to trump infantry, but to provide the minimal survivable armor for the soldiers inside to allow them to advance.
And toss firepower on there, because why not, if you've already got an engine?
So, as ugly as the fact is, the important thing is a tank's utility to survive long enough to support an advance. Not survive against all odds.