Just lost a game because of afk again, and yes it rly sucks.
The game already has a remake system if a player does not connect so why not create an extra surrender vote if someone goes afk.
The way this would work is if someone goes afk during the game and stays afk for a certain amount of time (5/10 min) you could vote to surrender (even before the 20min mark) and you would loose a reduced amount of LP (lest say 5). Same goes fot the winning team which only gains a small amount of LP.
If you are in a promotion the game wont count for you.
Premades will suffer the same fate as the one who goes afk (full LP loss / etc), to prevent manipulation.