> the advertisers have lost one extra person to sell to
Which is aligned with Musk's strategy thus far, but there's also a good argument to be made that that product should have never been needed if twitter was providing a decent first party client. They should have wanted to provide that to control the advertising. Letting the third parties take that up was a poor strategy -- business-wise that is, I get that people may have liked it and have used it for a long time and are probably sad to lose it.
I used to use Tweetbot which has now stopped working, as a result I don't use Twitter any more, the advertisers have lost one extra person to sell to.