The US could fly its drones with pilots comfortably sat in mainland US because the Taliban had no weapons able to shoot drones down. There was no dog fighting, no anti-satellite weaponry deployed etc.
Another reason is that warplanes are saturated with expensive kit like crazy. Yes the pilot is a major constructional constraint, but the main reason drones are so much cheaper right now is that they just aren’t designed as equally versatile platforms. If you wanted a full-fledged F35 drone replacement, I’m not sure it would be that much cheaper.
A different axis of the question, which came into play in the Azerbaijan-Armenia war recently, is whether we want few super-capable machines or much much more simpler ones. I think the jury is still out, but to me this is the interesting area of development.