I believe it is indeed a feature that the bracket of acceptable matches in matchmaker expands the longer people are waiting for a game. I think it will also prioritise the people waiting longest for a game which could mean that if you had 3 in the queue, one being much better than the other two, but waiting longer than either of them, he'll get the game ahead of one of the others.

That's the risk of the 1v1 queue. There is no facility to handicap one the better player with a weaker team mate. The loss shouldn't have burned many elos for you though.

its better to play later than not play at all.
Handicaping the better player seems ridiculous imo.like how would you do that handicap the mexes ? less hp? either of those changes entire game strategy and you cant plan ahead you would need to play diffrently because in case of less hp then normal counters dont work anymore you need the very hard ones.