Most of time, it's the juggle of time and resource available to you, but there is still a hard limit otherwise how about demand BG3 to also run on my antique knockoff NES? Cause they are too lazy to accommodate the hardware limitation? How about my smart watch? Or someone else's smart fridge?

Don't get me wrong, what you said in some cases but most likely the devs are told to push it out instead of make the game run better(on the target platforms.) There are no secret sauce to otherwise fit a game like BG3 to previous gen consoles.

Last, if you are really good at this optimization thing the whole industry will pay good money for your skill set.