Answering every comment for a year
It does not scale. That is the point.
There is an advantage available to people with small audiences that disappears permanently once they grow, and almost nobody uses it.
The advantage
You can reply to everyone.
An artist with two hundred thousand followers cannot. They physically cannot, and their audience knows it, so nobody expects it. An artist with four hundred followers can reply to every single person who says anything, and almost none of them do — because it feels like a small thing that cannot possibly matter.
Why it matters more than it looks
Someone who gets a reply from you stops being an audience member. The relationship changes category. They are now a person who knows you, and people behave differently toward people they know: they show up, they share things, they tell other people.
The conversion rate from listener to advocate through a single genuine reply is higher than any promotional spend you can make at that stage.
What a reply should be
Specific. Thank you to fifty people is worth less than one sentence responding to what someone actually said.
If they mentioned a lyric, mention the lyric. If they said it reminded them of something, ask what. Thirty seconds.
The window closes
At some point the volume makes it impossible, and that is fine — that is a good problem. But the people you reach during the period when you could reply are disproportionately the ones who stay.
The audiences that look sudden from outside are usually built during a long quiet period when someone was answering every message.
One caveat
This is a real cost in time and attention, and it is not free emotionally. Set a boundary — a window each day rather than all day — and hold it. Doing this badly, resentfully, is worse than not doing it.