It's lost 80% of it's value in 2 years, which usually isn't great. The most charitable view of X/Twitter is that it's now a propaganda platform that Musk doesn't mind taking a loss on in order to enact political change.
Im pretty sure he doesn't like that he is not able to make it more successful but i don't believe he regrets it.
He would have regretted it if it wouldn't have played out (and this game he is currently playing, is not finished yet) like it currently does. He said in an interview that he puts everything on one card now.
Edit: Also he gets a lot of valuation due to him being a cult or whatever. From companies surviving the AI phase we are in right now, if he can't get the nazi people on his side to buy his stuff, he is a very high risk.
He destroyed twitters brand and bluesky emerged. He destroys Tesla and other car makers making ground. SpaceX needs a lot of subsidies and his goal for mars is only a cult topic not a financial success topic.
If he does to the USA Gov what he did to Twitter, he will destroy the brand, reduce the workforce by 80% and reduce the value by 80% too.
The issue with him is, tha tin Twitter, the affected people had money. A missed payment of USA can literaly kill people.