There is fundamentally no profit in hosting images for free that people embed/link directly.
The same thing has happened to countless image hosts beforehand, and is going to happen to imgur too as soon as the music stops and the stacks of VC cash fueling the furnace are all burned away.
This is a great example of a market failure. Nobody wants a sustainable model where the image host can actually make money. As soon as they start taking away the "direct image links" feature, which is the only feature anyone actually cares about, and the thing that has zero possibility to make money, ever, everyone flees onto the next host, and the cycle starts anew.
We need another solution here. Maybe IPFS? Maybe torrents? Maybe some image hosting foundation?
It sucks badly that the Internet loses its collective image heritage every few years because somebody else thought that they could give it away for free and make it up in volume.