I've been playing Dota for whole my life and lately I have been getting increasingly frustrated that no option to concede exists in casual play

There's actually no reason for a concede option to not exist when playing a regular game of Dota 2. Normal matchmaking, absoultely nothing is at stake, no MMR, no real Money fucking nothing. Yet I am not allowed to gg out of a match even though pros can gg out an 18 million dollars tournament.

Let's be reasonable here, comebacks are an exception not a rule. You can't always comeback from a bad early game or sometimes you just get outpicked. It is entirely unreasonable for the game to expect you to play a match for the next 30 to 50 minutes when the outcome is already determined 15 minutes in and fuck all difference would be made weather you played with your hands or feet after that point.

I played Dota ever since I started with Dota 1 in elementary school and yes it was a serious game even then but one thing Dota 1 had over 2 is when one team stomped the other early, they would just leave and everyone move on to the next game and nobody would bitch and moan. Nobody wanted to play a lopsided game for an hour. That's not what fun is. That's work. That's frustration. That's the reason that will make me quit Dota one day when I am off school and have actual fucking work to worry about and no fucking time for this game's bullshit.

tl;dr: Normal matchmaking should have a gg out option. Right now normal matchmaking is all the cons of ranked play with no pros.