Imgur now blocks several VPNs and have issues loading embedded previews in several fediverse platforms. So instead of using imgur, you could use one of the following alternatives for uploading your images.
https://postimages.org/
https://imgbox.com/
https://imgbb.com/
https://www.imagebam.com/
Someone somewhere has to host the image. Realistically it should be the same people hosting the instance so you don’t run into cases where historical posts have all their images dropped. In an absolute ideal world everyone selfhosts their own images, but that’s an absolute fantasy.