In the future they can change the approach too and
both remove and restrict features
Unlike a lot of product categories... I don't really see a strong lock-in factor here?
Example: If you are heavily invested in Apple Music or Spotify, there's a lot of momentum there to keep you from switching. All your stuff is there (songs, favorites, playlists) and it would take a lot of time to re-find it on the other service, if it even exists there.
And streaming services like Netflix lock you in with constant reams of new content.
But what would be keeping me on some particular invite service? If I used Apple Invites for my last party two months ago... but I have decided that Apple Invites sucks now... I really don't see a lot of friction keeping me from switching away? The inconvenience would not be zero but seems minor.