I think it probably impacts in ways that are not obvious, essentially creating decision points on consumers to pass (for now) on certain games if they have a big enough "backlog" on Gamepass.
Outriders is on gamepass and still sold very well, so I don't know if Gamepass means anything at all. I know for me, without gamepass, I probably would have bought Nier and/or Returnal but due to having 50+ untouched games still on GP neither of the two games were enough to get me to pay MSRP at release. Mass Effect Legendary was though. Maybe you balance enough people who save money with GP that they'll splurge on some games that it balances out losses from people who wait.