The advertisers began pulling ads after ad agency execs met with him and failed to get satisfactory answers[0] and after he posted that conspiracy theory about Paul Pelosi. It didn't help that he ignored and then blocked the head of MMA Global just after the layoffs started.[1] If he wanted to keep advertisers on board this is an odd way to go about it.
The Ethical AI team wasn't 'silly', it was working on ways to make the algorithms used at Twitter more transparent to users, avoid bias, and potentially allow for multiple algorithm choices.
Subscription funding for Twitter is never going to work as Twitter Blue showed quite clearly. At best it'll result in marginal profit on a substantially smaller and less interesting site, dominated by a few voices and with many of its members leaving to other places. Nor will it block scammers, who'll be able to use stolen cards and other payment methods to pay for access the same way they currently pay for hacked accounts. It'll just be even cheaper for them.
Nor is $8/mo 'nothing' for large groups of people, especially in the developing world, and would result in them being excluded from the platform. Musk made one vague statement about the price being adjusted for different regions but nothing further has emerged on that.
[0]https://www.adweek.com/media/elon-musk-fails-to-answer-brand...
[1]https://twitter.com/LouPas/status/1588599808587345921?s=20&t...