Threads? Its usage is down 90% since its launch six months ago, presumably because they kept the people who could launch stuff and got rid of the people who had some idea of what should be launched.
The "Blue Checkmark" system? Released with no thought at all, absolute disaster. Steven King had to publicly announce that, despite indications to the contrary, he was not a paid user, and he felt it was important to tell people because he didn't want the idea that he was a paid subscriber to harm his reputation. Same underlying problem: the people who could ship things were still shipping things, but the people who could figure out what to make were gone.
And yes, they did drastically reduce cost...and much more drastically reduce revenue.
They shipped quite a bit of stuff, like the blue tick or revenue sharing. Other than Musk courting fascist and other kind of undesirables, twitter as a product is doing fine. It might go under though, but if that happens isn't going to happen because lack of employees.