I have one of each.

One will look at you like you're an idiot if you try and play with him. Cuddle monster is in your lap every time you sit down however. He satisfies his instincts with toys that struggle instead of run. A motorized fish toy is his current favorite. He'll "kill" it then parade his fish around the house yowling. I give him a good boy pet if he decides to show me.

The other wants to cartwheel through the air and destroy pop-up tunnels chasing twine for 5 minutes before it's back to bird watching.

You are right, those cats definitely exist, I am just warning against generalization.

A lot of houses (most houses) are purposefully completely devoid of the kind of stimulation cats need at a basic level.

Imagine walking through a house if you were as tall as a cat, most houses are just a series of blank, sterile surfaces without even any visual or texture variation.

You can't assume cats will just entertain themselves, they might be happy to do so but it is kind of cruel to assume they will given you are the one that locked them in a box. Like a bored predator, they need dynamic, reactive things they can discover, stalk and pursue, not static objects that are briefly compelling to swat at.