Disclaimer: I wrote this article and made this website.
There was some talk of this issue in the recent fediverse inefficiencies thread. I’m hopeful that in the future we’ll have a decentralized solution for file hosting but for now I deeply believe that users should pay for their own file hosting.
You’re not the first to think about this.
See https://aumetra.xyz/posts/the-fedi-ddos-problem - there an embed server is proposed, to be shared by multiple instances (ideally a great many would use just the one), which can host things like image files and previews.
There’s a big issue with this.
If malicious content like CP gets uploaded on to a server, obviously other servers do not want this to be replicated to their servers. So how would you solve this problem? Well they could give all moderation power to the original server they’re replicating, but that could be far too slow or they could even miss malicious content like this. Or maybe they even disagree about taking down certain things.
Another solution is that any server participating in the content mirroring could take it down for just themselves or for all the other members as well. The issue here is now you’re expanding moderation abilities, while also giving the other servers much more responsibilities.
It’s not as simple as wanting to replicate content. If you host it, you are responsible for any illegal content a user may upload to it. Not to mention laws vary by country as well. Ignoring the technical challenges here, it’s also mandatory that the other servers replicate the other servers data to also choose to be responsible for what gets uploaded. And that is a really big ask. The law doesn’t care about the technical reasons, they’ll just see illegal content uploaded to your server.