Earlier quoted context omitted.
While I think the app and service has gotten much worse in several ways post-Elon, I do see way less crypto spam than before FWIW. The "For You" tab now actually sometimes even surfaces tweets I'm interested in too now. Performance and general stability has absolutely fallen for me though, and the launch of the DeSantis campaign on Twitter was a technical embarrassment/disaster as far as I could tell.
My For You tab is excellent. But as to the rest I have to disagree. I get the same number of spam DMs, and I don't see better replies to big accounts. They are real people, but they're tiny follower and accounts who aren't relevant but paid for blue.
On other websites with recommendation algorithms, like YouTube, I can avoid this effect by viewing ragebait content in an incognito window, effectively curating my algorithm by opting out of it for content I don't want affecting future recommendations. But I can't do that with Twitter, because the login wall requires authentication to view more than the top three replies to a tweet. I wish there were some way to give the algorithm more intentional feedback on its recommendations.