It's different in the US. The gate agents, depending on the flight, for the last 10-30% of boarding passengers will say "we're out of room, we're checking your bags". So now you have to deal with that hassle. The lived experience is you have gate agents explicitly priming the anxiety.
OP missed the point though, also in the US, you can bring what's called a "personal carry on" and put it under the seat in front of you. Now overhead space is a non-issue. Just pack light.
