Maybe it's different in the US, but I fly constantly and have ever since I was a kid, and overhead storage space has never been an issue in my experience. At worst you'll have to put your bag a few seats away from your seat, but even then I usually travel with a pretty big duffle bag and have never had issues
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.
