On Slack it's only ever been an annoyance for me, because at least they visibly tell you when the message eventually fails to send. But on services like Twitter I feel gaslit when I've liked a tweet and then I scroll by it again later, un-liked. It undercuts my faith in the integrity of the entire interface. Any part of it could be lying to me in a way I may never find out about.

Overall I strongly dislike this UX pattern. Users should have immediate feedback about actions that haven't completed, but that feedback should only tell them the truth: that the operation has begun.