You can use imgur and paste a link to the high quality image, or fiddle with it a little to fit the limit. 100kb is fine for web use, imo. Crop, resize, convert to something like webp format… Instances are run by individuals, a server in someone’s bedroom. Not exactly a company with $15+ billion evaluation (dec2021) like reddit. It’s far from perfect, obviously. But it’s much better than I expected at first.