Re: W3C position on URIs http:// vs. https://

I'd argue that if schema's were used and dereferenced often, this would
already all be solved many years ago.

more common schema's like rdfs, schema.org and the like, would be receiving
tens of thousands of requests per second, likely far higher, have mirrors
all over the place, methods to consider a document from url a as url b in
place, integrity checks, versions, long caches, and all the solutions
widely implemented and available for things which are heavily utilized
around the web.

could you even transclude a foreign http schema, in a browser, from a
document elsewhere served over https without it being blocked or a load of
console error messages?

The elephant in the room here, is that schema's are hardly ever utilized,
or deferenced. Yes somebody will be doing it, some of you, but it's
certainly not being done at scale at web level. If it was, this wouldn't be
a discussion in 2023.