As an instance admin I gladly host user files.

One thing to take into account is that images posted by an instanceA user on an instanceB community will still be hosted on instance A.

So as long as an instance doesn’t host more users than it can handle it should be fine.

they are blocked in Australia, UK, Ireland, Iran and Afghanistan

Seems to be blocked for a friend from the philippines too iirc. Combined with other replies saying they can access it from some of these, I assume that list is outdated.

There are files I've uploaded to them since their service started that are still there.

After a while, files go into a "cold storage" and there's a wait until the server retrieves it.

The ‘catch’ is that running a service like this gets expensive fast and it’s the same with all the free image hosting sites.

Catbox is run entirely by donations with anything left covered by the owner out of their own pocket. If the donations dry up, it will eventually have to shut down. Again, this isn’t unique to Catbox, all the free sites could easily suffer the same fate.

While somewhat correct it still needs someone hosting your data, even if it’s you.

Slightly off-topic:

I never get why Ipfs is using these false claims about “uploading” to the Ipfs and having it “permanently” stored. In reality it’s just Torrent, someone has to have the file - if no one has, there is no file. In theory one could make the same file available again in the future but all the hashing settings have to match with the previous or you’ll get a different reference hash.

The hardest part will always be moderation. It will be incredibly difficult to prevent smut and CSAM propagating without people actively monitoring what content is being hosted. But even if you assume random people have the time and are ok with seeing and reporting/filtering out that content, you’ll still never combat advanced cryptographic steganography techniques; a picture of a flower might have content hidden inside it somehow that encodes the bad content in a way that you’ll never find it. On top of that, moderation is work that no one wants to do for random content they don’t care about, but without people hosting content they don’t care about, links will die too quickly to be useful. Imagine if you posted an image to a niche community, and then had to keep your system on for hours, days, or weeks, ready to seed it to the one lurker who happens across it, and then maybe they also seed it.

tl;dr it’s a very difficult problem…

It's true, but there's some pretty reasonably priced S3 compatible containers now. To the extent I'd only start getting concerned at the 1TB mark.

Of course I also am not going to complain if people use hosting sites and prolong how long it takes to get to 1tb :p

In addition, help out your instance admins by resizing the image if you don’t need it in high resolution.

Uploading a 250Kb file rather than a 2.5MB one makes a difference when thousands of users are doing it.