Why Do I Have to Wait for Aholes Who Disconnect in Losing Positions?

I'm a steamroller and sometimes I steamroll through my opposition within a few seconds. But then they disconnect and I have to wait 2-3 minutes for my win to be registered. Perhaps there should be a faster/smarter way to register this win?

Your opponent is entitled to use his time as he wishes. Of course, letting the clock run down in a totally lost position is very unethical indeed and I understand it can be rather infuriating during arena tournaments, but it's still within their rights. Furthermore, if they disconnect from a game, you can claim a victory in 1 min and if they leave the game while still having an active connection, the time required before you can claim a victory is even lesser. And if your opponent lets his clock run down in this manner frequently, he'll be slapped with a temporary lobby ban. To answer your question though, no, there isn't a faster/smarter way to register this win.

Go to their profile and report/block them. If that player does it often, Lichess will send them scary warnings and eventually ban them if they continue.

Personally, I think after a minute of inactivity (maybe 3 or 5 in longer games) there should be a pop-up on the page saying "Are you still there?" and if the player doesn't click on it in 10 seconds, he forfeits the game. This way, if the sore loser wants to waste your time, he also has to waste his own time and click those boxes every so often.

Somebody in another thread suggested that you take solace in the fact that you made your opponent so salty that he ragequit.

It's because you are the steamroller! Your reputation precedes you. You flatten anyone that gets in your way! You are a tactical behemoth on steroids! You are fear! You are chaos! What else can patzers do but flee when stood in front of the "steamroller"?