The numbers
The numbers are an integral feature of every modern social media platform. They comprise likes, shares (e.g. retweets), follows, replies, views, and whatever other forms of engagement apply to the particular platform.
Engagement is one of the most important metrics for platforms that rely on advertising as a source of income. When the numbers go up, companies are willing to pay more money to advertise on the platform. Unfortunately, platforms are generally dogshit at posting, so their efforts are better spent convincing their users, through psychological conditioning and dark patterns, to make the numbers go up themselves.
There are some platform-specific browser extensions that remove the numbers. If you're willing to restrict social media usage on your mobile devices, this is one of the few options that lets you have your cake and eat it too I've documented some of the Twitter-specific options on my "never tweet" note.