What does this mean?

This means that the people who follow influencers here are usually not reading anyone else's stuff. So everyone else crowds into their threads, in the hopes of scraping together some crumbs of attention. Which creates an articifial engagement bump and catapults the same people to the top of the trendlist over and over. And newbies only follow the people at the top of the trendlist.

Wash, rinse, repeat.

This is the most antisocial social media algo ever designed.