Lol, they either lied or failed if they really tried to make it closer to the core rules and decided it didn't work. Solasta is another 5e CRPG and it nails the core rules that people keep asking Larian to change back to 5e, most notably the action economy of 5e. Solasta lacks the polish of BG3 but the tactical combat is far better and a hell of a lot more fun than BG3, IMO. If you have a chance you should check out a gameplay video of Solasta and see for yourself that the core 5e rules are easily implemented and entertaining. Hell they even included the 1 free action per round but they gave players a bit of headroom in that you can use the free action to swap a weapon set, so you can switch from sword and board to two hander as a free action, where you can't do that in table top.