I am not a regular Twitter user but I have already heard of people who plan to leave it. I certainly won't be paying for it.
Nor I, there's way too little value in it for me to consider paying for.
Musk seems intent on demonstrating that he's really not as bright as he would have us believe. As others have pointed out, the users of Twitter are the product - it's the advertisers that are the customer. If Twitter takes steps to reduce its product range and size, then there will be insufficient customer value delivered to the advertisers and they will stop buying the product. Who is going to buy advertising space on a platform that only appeals to Elon Musk Fanbois?