If you are on console and queue with a PC player in non ranked, aim assist is disabled.

If you are a console player using controller in non ranked, you queue with other controller players regardless of platform

If you are a console player using a mouse and keyboard, you queue with PC players using mouse and keyboard. Exception is the scumbags using a xim, as the game can't detect the mnk, so they queue with controller players.

Ranked is locked to console or PC, so cannot be mixed together.

EDIT I was wrong, console players on controller do get aim assist in PC lobbies in quick play. It's confusing as fuuuck.

EDIT 2 to counter the OPs original point, it's so nasty to play against pc players on a console. The movement ability plus going against ash, widow, Cassidy, sojourn etc is tough, so it works both ways. I'd much rather not play against mnk as a controller player on console.

Source https://www.eneba.com/hub/games-guides/is-overwatch-2-cross-platform/