Although ad revenue is the most likely reason for Twitter's actions, I think there's also a larger issue at hand. Musk has made it clear that he's the boss and will fire who he wants, ban who he wants, and reinstate who he wants. The very idea that there are other applications out there that could deliver an experience not in line with Musk's vision seems out of line with his authoritarian impulses.
Ooof.
I stopped using Twitter after my preferred app stopped being able to connect.
Twitter will collapse when enough left wing people leave.
Right wingers don't build communities, this is primarily why RW social media sites perk fast and collapse. They're insular and LW people don't bother with RW soc-sites. Thus RW people have no "libs' to own" that is necessary for keeping any semblance of cohesion
I mostly used Tweetbot, but I really liked the Twitterific refresh animation.
Never liked the official app.