Unfortunately there are a plethora of answers and in an ideal world you could choose your own.
But in this world? You get whatever dirty peasant scraps Blizztivision hands us and if you don’t act thankful for it then you get slapped over the head and told ‘bad player, bad!’
On the other hand, nobody and nothing stops you from smurfing. Soo-o-o-o, it probably dawns just why smurfing is so rampant when it’s such an easy workaround for so many faulty systems nobody gets paid to bother with any longer…
A lot of leavers would also rather log out for 24 hours than have to play leaver games.
Heck, many people think they can log out for a year and come back to no leaver penalty. They are surprised when it has gone nowhere.
Proving the leaver system is a great deterrent for leavers.
Being “locked out for 24 hours” or “playing 1 QM/ARAM” (instead of winning it) is no deterrent or threat to a troll or constant leaver.
1 such leaver also ruins the game for 9 other players, so removing them until they fix their connection or stop leaving is important.
The whole “leaver” concept is arguable.
I more often see tilted people running into towers to force a loss faster, than I do bots because somebody left … just showing how useless this whole method is.