To prevent people from spawning in unreleased content that is in the game, giving their group the maximum cap of in-game currency, and so on. Tamps down on the boosting market.
I'm not sure how requiring an account in addition to the Steam account is enshittification. Especially given that it was intended to be the case from the start, but they temporarily disabled it due to technical issues.
I'm pretty sure Pepe was only temporarily coopted by the far rights, and has since been reclaimed.