> GPIO can be added via tons of USB to GPIO boards out there.
Depends on the use case. USB adds a few orders of magnitude more latency and jitter versus what's probably just APB.
Which only matters in very niche usecases though.
Most of the stuff just flashes LEDs or reads a switch. Doesn't matter for that. And for more intelligent stuff there's i2c or api which have their own interface boards.
GPIO can be added via tons of USB to GPIO boards out there.
But I agree - lot of people tend to buy the Raspberry Pis for home servers instead of just opting for used mini-PCs from secondary markets. Even a 7-8 year old Intel CPU in those mini PCs will vastly outperform a Raspberry pi. Even the Raspberry 5. Plus, better I/O options and storage with mini PC.