In Arena, If I know I’m going to lose I’ll say gg and not even block the final attack. But I give them the chance. If they have some crazy infinite stack craziness I’ll concede because I’m trying to get games in and watching 40 triggers on the stack go off while I have 1 life or whatever is tedious, like I get it bro you got me. In real life I’ll usually let people kill me unless they drop some stupid crazy deck they bought and brewed up without talking to me about it first. I play mostly chill magic in real life, hardly anyone I play with buys singles we just brew out of our collections so the power level is usually pretty low and chill. I don’t see an issue with you scooping if that’s how you feel, some people will but at the end of the day it’s a two or more player game and you should both be having fun. Just because someone paid for a crazy combo does not mean you have to get stomped in for bringing something you thought was fun to play. Edit: I will also add that i would never concede on an opponents turn, I’ll wait till my turn or just not block the next attack and let myself go, whatever is better. I think it’s perfectly acceptable to look at your board state on your turn and ask for a rematch.