Oof. Not wanting to play your own game after you have allegedly finished developing it is never a good sign.
The literal exact opposite of that is true.
A dev who playtests their own game is likely to miss a ton of bugs, because they know how things are "supposed" to work and will tend to play that way, so you'll get one "clean" path through the game and miss tons of other game-breaking bugs.
The whole point of getting other people to playtest your game is because they will play differently than you. They will play "wrong". They will do stupid things. They will complain about bad UI choices you've grown accustomed to. They'll notice mistakes in dialogue that you completely miss because you're used to seeing them and your brain doesn't even register anything wrong anymore.
In short, a dev
shouldn't play their game after they finish an update. They should be forcing other people to play it for them. And then they should go back in and fix all the stuff those people manage to break.
Besides which, if you've been working on content for months (whether that content be a game, a movie, writing a novel, editing a longform YouTube, etc), odds are pretty high you're going to be burned out when you finish even if it's one of the greatest things ever made. Creators pretty much
need to take breaks from time to time if they want to keep creating.