For a long time now I have been using imgur, but I got to thinking and wondered if there was a better site.
It would be nice if the site also allowed linking directly to the image file instead of having to go to their site. Also, an option to delete the image in-case I accidently dox myself after posting a screenshot.
After a bit of searching, I found PasteBoard and ImageVenue, but I haven't tried them out yet.
From someone who has tried pixelfed, it is basically a photo post filter for mastodon. You can see photo posts people make on mastodon from pixelfed and you can see pixelfed posts from Mastodon. So as mastodon apps improve and you can filter posts by content type (maybe you already can?) than pixelfed is basically irrelevant and/or equivalent to a photography focused mastodon instance.