I don't want spam in Bitcoin. I don't want my SDD filled with idiotic JPEGs. However, it's likely true that ultimately you cannot prevent this, at least not without Bitcoin losing some functionality or innovation. What I mean by that is, that yes, you could conceivably enforce very strict data checks, like signature validations, etc, but that might be either too expensive or prevent unplanned innovation in other areas. But even if possible, no one is actually pushing for this, only filters, which can be easily bypassed by miners setting up alternative protocols for accepting non-mempool transactions. Let's take a step back. Why do physical world collectibles, like paintings, memorabilia, etc. have value? Most don't, but a tiny subset do, because of some kind of unique narrative. A story around the object, and if course its scarcity. This is unlikely to be replicated to any significant extent by digital media. It's just not very compelling to own a digital original, because it's literally indistinguishable from any of the infinite possible copies. And any accompanying narrative is going to feel disingenuous., because there's no distinction between "original" and copy, and because any narrative is going to feel much weaker. So, in this ongoing civil war, I'll take solace in the belief that there is just no long term JPEG economy on Bitcoin.