Whoever saying “Twitter is dying” does not understand how tech companies or general businesses work.
We do have a typical example in the past showing that social media cannot be simply dying. MySpace used to be a very popular social media platform in the past, but it became more targeting on artists and music sharing. MySpace changed and narrowed down its target audience. However, it is not dying.
Tech companies, most of the time, has invested lots of money, and it cannot be simply dying.