That is exactly the point. There is nothing inherent in an Xbox that prevents it from running a web browser. Only our collective acceptance of the practice of denying users control of their devices, and letting these arbitrary restrictions contribute to e-waste.

Because they can't?

People were making a lot of noise about Sony retroactively removing functionality not too long ago.

But even if we accept the bogus argument that a console (a behemoth CPU with 100s of watts of power available) is not a general purpose system, that's not relevant:

Why should a company have to go through Sony or Microsoft's stores to buy games for their console? What makes consoles somehow different from phones? - I would put money on the primary apps people buy from the App Store being games?

Claiming the Sony/MS make a loss on console sales isn't relevant either - firstly because they're charging ~30% on games with an average sale price in the region of $60 they make up that "loss" very quickly, secondly neither company expends significant (any?) resources developing features for their consoles once they've been sold (vs. Apple that is still providing major updates and functionality to devices 5 years after they stopped being sold)

I actually used to do it. When I was younger, my parents offered me a PS3 and I had no personal computer of my own. So I installed Ubuntu on my PS3 (it was possible at the time, until a later patch where they disallowed it) and used it both as a desktop computer and as a PS3. That was pretty cool.

A PS5 today could easily run whatever desktop OS.