While I do agree both are viable, and mostly just doing what you are used to works best, I have to disagree in a vacuum.

I find that cracking on the edge of a bowl tends to push the shards of the shell inside and rupture the membrane if you hit a bit too hard, and then the egg takes it with it for a ride. When you do it against a flat surface, it’s easier to get an even cracks you can pull apart without the membrane breaking, which keeps the shell together. Honestly, just gives you more of a margin of error if nothing else; if you’re super used to it, as you said, it’s probably not a problem worth trying to fix.

I don’t know if doing it one handed makes a difference. just my two cents as an ex-professional baker.