Why have 100+ people? Why not have a small group of high-quality friends, instead of a large pool of low-quality friends?
Once I realized that, it was easier to just delete facebook, and keep in touch with my close friends and people that are in similar studies to myself by using group chat messages, emails or just face to face (not so much this option in 2020)
You can and should. Although at a certain point the benefit of being connected to those people via social media as opposed to say, a group chat via text message or an app like Discord/Slack, diminishes greatly. I think that's the paradox of social media: the only thing it does well that alternatives don't is connecting you to lots and lots of people, many of whom you barely or don't know at all, but the quality of the experience degrades with the number of people you are connected to and the weakness of your connection to them.