Google Drive might be a good middle ground. ?
There have been quite a few images linked from Google Drive that don't work for whatever reason. Of course, this analysis is skewed by only noticing the ones that don't work, but I don't recall having that problem from any images on another service.
What I've seen cause problems is when someone changes the photo permissions
after linking to it here. When that happens, the hosted image is given a new URL, and the old one doesn't work anymore. At least, that's my vague memory of past problems. I think, if you get the permissions set the way you want them, then linking works fine. I can't find the thread where I described this in detail once upon a time.
Hmmmmm.... Maybe that was Flickr, not Google Drive........ ??
Yep, that was Flickr. Never mind.