Would you add likes, upvotes, follows, or other social media features?

No. Like buttons provide no useful insight to the author, as opposed to "I like this project because it..." or "This project would be better if..."

The Facebook like button, which started all this, is a great source of evil in the world, for many reasons. Read The Age of Surveillance Capitalism by Shoshana Zuboff for all the details.

We don't want popularity contests; we don't want people to feel good or bad because of how many people liked their project; all that has nothing to do with learning computer science.