I'm going to add another perspective as a person from a different side of fandom.
One of my navite languages is Russian so most of my time reading and posting fanfiction was spent on Ficbook. The thing is, unlike ao3, that site is monolingual (recently they tried expanding by creating separate sites for English, Spanish, and Portuguese I believe, but they aren't well known). And while there are a lot of native Russian speakers outside of Russia (like me), most of their user base is in Russia.
And the thing is... They are for profit site. They have ads (increasingly more and more over the years). They have "gift" system where you can pay real money to send someone a digital sticker (that back in the day was original illustration at least - now they are heavy on AI-generated shit), and the site gets all that money. They have paid features (e.g. free accounts can only download 10 fics per day and paid accounts can download 100). Some users suggested to move site to donation-based system (or another tier of paid accounts where you'll remove ads in exchange of donations without getting other paid features - ppl wanted to support the site but didn't want paid covers and promo and stats and shit). The site refused, saying that project won't survive on donations, it's not a realistic system (which might be true since they are for-profit and they have paid developers on stuff, but still). So, they kept relying on ad revenue and paid accounts.
And because of that they were trying to walk a thin line of "don't be banned by Russian government" for years. Technically, they moved their servers to EU long time ago (though as far as I know they still hire developers in Russia). But they rely on ads traffic and paid users and ban would mean they lose a big chunk of it simply because Russia is cracking down on vpns and there is some laws around putting ads on banned sites which cuts out actually relevant companies who could've advertise there and bring more clicks and more revenue.
After annexation of Crimea the site added a rule forbidding to write fanworks about "recent world tragedies and political conflicts" with a limit of "6 month after the situation stabilised". However many people noticed that the thing that actively gets blocked is anything pro-Ukrainian related to Russia-Ukraine war, for example a work where author supported Ukraine and urged russian ppl to protest in his author's notes, not in the body of work.
While they don't have it written in their rules, the site deleted multiple works with graphic depiction of suicide because Russian government bans anything beyond brief mention.
And in the recent years, when Russia introduced stricter laws about "gay propaganda", the site added rules about tagging: the category and all additional tags have to be correct, if you miss a warning or mods decide your off-hand mention of lesbian couple is too much for "mentions of f/f relationships" tag, your work can be forcefully edited or in most cases just deleted. No warning, no emailed copy. If you don't have a backup elsewhere, you're fucked.
At one point they considered creating "Slashbook" and basically moving all queer works off the main site into its own reservation, so in case they'll get a ban, it won't affect the main site. They even started accepting donations for that but soon quietly ditched the idea and started making an english fic site.
A year ago, when Russia decided to ban the site completely - for many repeated violations of "gay propaganda" laws they tried to resolve it... by soft-blocking queer works themselves, so a user located in Russia opening a fandom tag will see "this work is not available in your country" placeholder on anything with m/m, f/f ships, trans characters and some kinky tags. The placeholder was non-clickable, didn't have link to work or the author. The authors from the area would be able to post the work but most users won't see it. And some smaller russian fanfiction sites like fanfics.me of fanficus.com were able to get away with it - but Russia refused to unblock Ficbook and basically ignored them since. yay.
So. The site dependent on ads and profit will think about ads and profit first, their users second (if at all).
