If your desktop is windows, you might have games that don't play perfectly or at all on Steam Deck. I haven't had major issues yet, but I've seen some glitchiness and text that is hard to read on the small screen.
I've still got a good two dozen "Deck Verified" top-tier games to play through before I even think about it. And even then I'll rather go with a launcher that supports my Epic and GoG game libraries before resorting to Windows.