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/
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.
@aleph As an instance admin myself, we are looking into fine-tuning those settings to limit uploads of an x amount in file size. But are we are looking into some thumbnail library to reduce the image sizes indeed.
Saving images as webp gives massive savings, and I think everyone can view them nowadays.