The tac vest (as far as I understand, anyway) was designed when we were pretty much just engaged in UN peacekeeping operations, mostly in Eastern Europe. Enough capacity to carry some rifle mags & grenades, but obviously not designed for warfighting.
Then 2001 happened, and we were caught unprepared for Afghanistan as our focus for the past few decades had been low to medium intensity conflict throughout Eastern Europe. (Croatia, Bosnia, etc etc.)
During the Afghan war years, I know some units allowed their members to purchase their own rigs - and the unit would reimburse them. Same with boots. (I can't see that happening these days, the Afghan war days were a different work culture)
Whatever we go with, it needs to be modular. A member primarily using a C7 has entirely different requirements than a C9 gunner, C6 gunner, 203 rock lobber, etc etc 0.002