I started YouTube when having contacts was still a thing. Virtually everybody I was subbed to was also a contact. And there were more people who were contacts of mine than subscribers. Many of us kept in touch and though I didn't have a "fan base" I had a group of people who were united around mutual interests, and quite a few of them. Eventually YouTube did away with that, and because of that, the number of emails I got per week went from like 200 to zero. A lot of people stopped interacting as much, they didn't see the point, because when you were "Contacts" with somebody, you had access to a side of their account regular suscribers never saw. Now, if you want a big fan base, it's all about doing what you can to get subscribers. You'll be making more content than interacting, and the social aspect of it takes a back seat, but not for long, because YouTubers still like interacting with one another, so you have to really apply yourself and spend a little time down in the bullpen communicating with subscribers as often as possible.