⭐ Merited by JayJuanGee (1)
That's the thing: there is no JPEG ownership, it's meaningless! It only "means" something on a made-up system, which only means something to the few people who are in on it. To the rest of the world, it doesn't mean anything. And on top of that, anyone can claim "ownership" of any image, with or without having the rights to do so. It's a scam.
You're right, with Ordinals there is no proof of ownership on-chain -- it is only enforced at the Ordinals protocol level. With Runes, which I haven't really looked into, supposedly the proof of ownership is on-chain, although I don't know how it works.
There was a saying by Joe Looney, an early Counterparty user, wallet dev & former Rare Pepe Scientist, "the token is the art." A lot of famous Counterparty "NFTs" (quotes are needed because most are actually fungible) don't have the artwork attached to the token at any level, or the original image-containing URL it pointed to on-chain is broken. Doesn't affect the price or collectability of the token in any way.
https://xchain.io/asset/RAREPEPE
With Counterparty, the token itself is the art; the art is merely a representation of the token.
With Ordinals, people are basically just collecting dust, which is why I never got into it.
Runes is basically a more crude, expensive & better-marketed Counterparty AFAICT.