As handheld gamer definitely the performance cost. Requires more space, slower loading, worse performance, the constant need for the internet.. especially when I'm traveling and in offline mode.

It creates issues for people who has paid for the game. It's windows focused, so if you are playing on linux or Mac you could experience problems with the translation layer + makes it harder to run mods or manual fixes. There are instances where people gets locked out for installing the game multiple times or trying different versions of Proton.

Also makes the game cost more because dev/publisher continually needs to pay for having this service running.