Fake news was prominent on there way before Elon bought it. They have years old studies showing the amount of bots and how many people are essentially shouting into a void.
If anything, I think the biggest detrimental was how quickly it accelerated the death of that platform; it's a great source of news, real time info, etc, along with all the nonsense but it's never been as a popular as Facebook or as ubiquitous as insta, and tik-tok/Snapchat basically took the younger demo.
It's why bluesky has actually been seen as the first new directly viable competitor for social media since Facebook