Some people have a lot more influence than others, and the influential people are disproportionately on twitter.
Also politicians.
That is the whole problem though, isn't it? A few hundred random people on Twitter are often more than enough to manufacture a wave of articles across multiple news websites and newspapers.
Twitter isn't important, the problem is that influential entities think that Twitter is important (and representative).
Which makes it important..
See: Facebook's declining usage, and the rise of TikTok.
Social networks are all quite replaceable, there are no exceptions.
Twitter won in its micro blogging space (there were numerous competitors for a brief time, way back), however it has never been a stellar product. It can and will be replaced if Musk turns it into a disaster.
It will be funny of the Blue Checkmarks have to form their own social media platform - or in incredibly irony - end up in one of the "right wing" platforms as a refuge of free speech.