The thing about the jpg ones is that the jpgs can't be stored in the blockchain, so what is actually stored is a URL to some server (and that URL endpoint could be redirected elsewhere, the server could go offline, etc).
The other major use case I see touted is "own your game objects and bring your objects to different games" but 1) why would a company spend resources supporting an object they did not sell you and 2) could this not be handled more simply on e.g. Steam? (yes, locked into a service, but that's just the way the industry is and I don't see why it's worth the time and effort for them to change that)
I do see how potentially a blockchain that stored actual data, e.g. some JSON, could be of more use. However, I struggle to find cases where just a regular database wouldn't be more practical. I guess it would be limited to cases where auditability and visibility of changes are topmost concerns, and where it's important that anyone can have a local backup copy at any time.
If you have some examples of where this technology could be one of the best solutions, I'd love to hear them. The blockchain does fascinate me but I feel like it's often a solution in search of a problem rather than the other way around.