You can already do all this. In practice, I've never seen a site render its text and ads to a canvas to make things difficult for me.
IMO, the bigger obstacle to "content that can't be linked, saved/archived, mirrored, cached, shared, translated or made otherwise accessible" is the "fundamental architecture of the web": HTTP. You can't link it (who knows if the person who clicks the link will get the same page?), you can't cache it (who knows when to invalidate it?), you can't mirror it (who can enumerate the dependencies?), and so on. Something like IPFS would fix these things (and should fix these things). But in practice, a fairly cacheable, linkable, mirrorable, sharable web has been built on HTTP and I expect nothing much will change when wasm is thrown into the big vat of web technologies too.
IMO, the bigger obstacle to "content that can't be linked, saved/archived, mirrored, cached, shared, translated or made otherwise accessible" is the "fundamental architecture of the web": HTTP. You can't link it (who knows if the person who clicks the link will get the same page?), you can't cache it (who knows when to invalidate it?), you can't mirror it (who can enumerate the dependencies?), and so on. Something like IPFS would fix these things (and should fix these things). But in practice, a fairly cacheable, linkable, mirrorable, sharable web has been built on HTTP and I expect nothing much will change when wasm is thrown into the big vat of web technologies too.