I also think ANY game should have a “full potato” mode capable of running in older computers with NONE of the fancy graphics stuff that we have access to today, despite having a decent computer now.

Problem is that the fancy graphics stuff isn’t just additive.
For example, raytracing is actually relatively simple to implement, since you just make light behave like it does in real-world physics, according to a couple relatively straightforward rules and material properties.
Lighting without raytracing involves tons of smokes and mirrors hacks and workarounds. For example, mirrors were often faked by building the same room behind the wall, with everything inverted, including the player character’s animations.
So, making a game with potato graphics typically requires building a second version of the game.

Of course, there can be a mode that does just turn off the additive stuff, so only that which does not require changing the game implementation. But that can just be one of the graphics presets…