This is probably gonna come across like I'm being kinda bitchy, and maybe I am, but it's been on my mind for a while now. Ever since I saw a post about strict adherence to true love and monogamy poisoning fandom.
And that post was 100% correct, but I'm gonna take it a step further.
The general decline in popularity of fanfic in general is also poisoning fandom. Every day, I see posts on Reddit and Tumblr and Twitter that are basically "wish lists." Things OP would like to see their favourite character doing. Things which are often fairly popular fic tropes, because lots of people want to see their favourite characters doing those things. And then I'll go into the comments or replies, or whatever you want to call them in a social media environment where comments don't exist, and I'll see someone reccing that person a fic that fits their bill.
And not always. But often enough the response from OP is along the lines of "I don't read fanfic."
And it takes all of my willpower to not tell them to get use to disappointment, because the canon doesn't exist to please them and them alone.
Mainstream media is popular because it is mainstream. It has to appeal to as broad an audience as popular, which means your niche little wants are not going to be met.
Take the Loki series, for example. Within fandom, Loki's Jötunn heritage is extremely important. People want to know how he grapples with this aspect of himself, and how, if at all, he comes to terms with it. The series did not go into this like a lot of people thought it would. But as far as the MCU is concerned, this aspect of Loki's character has been explored and dealt with. Was it done in a trope-satisfying manner? No. Did we even see him come to terms with it on camera? No. But it's clear by Infinity War that he had, on his own, somehow reconciled that aspect of himself with his own self image.
If you want more of that, you're not going to get it from canon. But there are over 2800 fics on AO3 that will give you more. And those are just the fics that are tagged for this trope. There are plenty more where the author probably did not know that tag exists.
But I'm increasingly convinced people don't actually want these things. People would much rather complain about not having them. It's easier to spend two minutes complaining about something not happening on your TV screen than it is to read a novel-length fic that gives you the emotional payoff you feel is lacking from canon.
Taking Jötunn Loki again, because that's one of the most common complaints. If I go through that tag and filter for non-crossover WIPs, meaning fics people are currently writing, there are a few fics on the front page that have large hit counts. These fics have juggernaut ships, or are "drabble collections." But a lot of the fics in this tag have a couple hundred hits at most.
Okay, maybe people don't read WIPs. That's fair.
When you filter for completed only, all those high hit-count fics disappear. Most of what's left have under 1000 hits. Many have under 500.
But what? It's not canon, so it doesn't "count"? Marvel, or Disney, or whoever produces your canon of choice, does not give a fuck about you or what you want. You can complain all you like, and it's not going to change anything.
But that thing that you feel is missing from your canon, whatever that canon may be, exists. It exists on AO3, because someone out there agreed with you. And they've got 200 hits and three kudos, because you'd rather bitch about it than actually get what you want.