Fortnite PC Controller Crossplay?

If I connect to Fortnite on the PC controller in the lobby I still play against PC players?

Or if someone in my group is the PlayStation or Switch plays and I connect controller s.PC, then we play against controller or PC player?

No matter what you connect to your PC, you will always be recognized as a PC player. In the first case you are still playing against PC players and in the second case you are playing on the Crossplay servers. So against consoles, mobile and / or PC players.