I'll stricly talk about the ads at the end of each update because the other practices like spam, asking sub4sub and stuff, gives me a major "attention whore" kinda vibe xD
I used to think people who reminds their audience to like and subscribe, to be a sellout moves but lowkey I feel most of people are ghost consumers (which imo can be/is a toxic behaviors in some extend). Sometimes we need a little reminders that hey it costs nothing to support the artist we appreciate with a like or/and a comment.
Authors provide value to us, in this case for free so in my opinion if they reminds people to give back that same energy if they can, i'm okay with it because it should be an instinct to begin with.
At the end of the day, it's up to you if you want to support or not.