I think what might help the whole "low engagement in fandom spaces driving creatives out because they don't see the point in sharing anything only to get crickets or critics" is not the shaming tone of "look this is how you get nothing, you entitled shits" that tends to be very pervasive, but rather pointing out how actually rewarding it can be to leave nice comments.
I like to leave very long rambling comments on people's fics and that has actually netted me some very real, genuine friendships and we've become cheerleaders for each other. My friend has a D&D Podcast that she doesn't get ANY sort of engagement out of, so I started listening to it at work and livereacting the things I enjoy about it and showing her my investment and it makes her very happy and it makes me happy that she's happy.
Being nice to people... is actually a good enough reason to do things, shockingly enough. You don't have to do it. No one should shame you for not doing it. But it doesn't actually cost anything to make other people happy, especially if they created something that made you happy.
I'm going to take this away from fic writing for a second and talk about community in general.
Humans are social animals. We crave connection and community, and one of the constant complaints about modern society is how isolating it is.
But I look back on how my parents built a community every time we moved - and as an air force brat we moved more than most.
You want neighbors you can borrow a cup of sugar from? Hang out and watch a lunar eclipse with your entire street block?
Someone, anyone - and that person can be you - needs to do something to get that ball rolling. Make cookies and bring a plate to your neighbor, just to say hi. Wave when you see them outside. Offer to help shovel their snow - or just go ahead and do it for them (my neighbor sometimes does this for me).
You get the community you put the effort into building.
Let me say that again, with emphasis.
You get the community you put the effort into building.
And if you nope out of that, you are left passively accepting whatever community other people put the effort into building.
Whether we are talking irl or online, it's true.
To bring this back to fic comments - it's an easy way to build your fandom community, and can even lead to friendships and fandom based chat groups.
You don't have to engage, ofc. And different people have different comfort levels, so if it's really not something you are comfortable doing I won't judge.
Just be aware that that's the type of community you are helping build.
