Wholeheartedly agree with this.
I am on Patreon for some three years now. Only yesterday did I get a pledge from someone with whom I hang out on semi-regular basis.
My friends, in general, don't watch my vids. When they mention it, the dialogue always goes like this:
"Oh, I haven't been watching your videos / Oh I haven't watched your video on _____!"
"You don't have to! Watch if it if it interests you and if you find the time!"
However, while I say that, I do opposite myself. I try to go to their exhibits, read their books, watch their content etc. I don't think that they're bad friends or anything of the sort, it is just how I like to show support. But yeah, in general, friends make a very poor fan base.