Places that prevent selection completely is not something I encounter that often.

What I do experience regularly is places where selection is broken or unnecessarily fiddly. On iOS I find it often easier to screenshot and select in the image.

Screenshot, select, paste is a much smoother workflow than trying to select what I want three times, failing, selecting too much on one end, not enough on the other, copy, paste in Notes, fixing it up, select and finally copy what I wanted in the first place.