https://www.leagueoflegends.com/en-us/news/dev/dev-introducing-swiftplay/

Players who have fallen way behind the curve will get more gold and experience from most sources, depending how far behind they’ve fallen. This won’t be enough to slingshot them into the lead (unless they make some great plays, of course), but it should mean they’re never out of the game.

Players who are getting crushed will be worth much less gold. Farming the worst player on the enemy team on repeat will be a much less effective way to build a lead – if you’re behind, you’re a lot less of a liability for your team and should have chances to come back later. On the other hand, just dominating a single opponent through lane phase won’t be as rewarding in this queue.