I don't doubt the relevance - I just think we may be ahead of our time, in terms of bandwidth and storage. It takes money to host high-bandwidth applications and the blockchain multiplies these costs. And then you have to face the issue of not having revenues to pay for these costs.

The blockchain must have multiple copies of the same data in every node (=inefficient), while a popular image host may need just one data center. (centralized = much more efficient).

Then you have issues like malicious spam, where uploading large photos may be done on purpose to fill the blockchain and make it unusable in terms of size. And these images can be crafted in such a way where they may not even take 5% compression. Now at that point you'll have to ...charge fees to even host one image in order to prevent abuse, and when you do that, you may have lost the game entirely to the centralized & free competition.

Now all these will be solved as technology evolves and the sizes of images become trivial compared to technological capabilities.

I can envision a hybrid model working right now, with a small parallel blockchain for images, but only on a somewhat expensive fee-basis (which is unattractive), otherwise I don't think it would work.