> I do think that it would be great if there were a way to tell a web browser through its Dev-thingy to actually serve a folder to itself as if it were served by a bona-fide web server with HTTPS.
I'd like to plug Beaker Browser as an amazing tool for getting started with barebones HTML, CSS, and JS. I would say Beaker marvelously fulfills this wish for a browser to serve a folder to itself.
Because it is built around the peer-to-peer dat:// protocol, it also ends up being "local-first" regarding web pages that you write with it (as well as sites that you decide to seed).
@staltz has an interesting presentation on the utility of Beaker Browser: https://staltz.com/beaker-frontend-dev-dream-browser/#0
On the other hand, I don't know enough to speak to Beaker's capabilities with XmlHttpRequest.
When I was a teenager learning how the web works I used the free version for MAMP for this. It was super straightforward, as I recall. Open it up, choose a folder, and serve. I think it even included PHP.
> loading other files with XmlHttpRequest
simple functionality? To me that actually does sound kind of like an 'advanced' thing to even think of from a beginner's perspective... i.e. someone who's just trying to learn to make a web page with perhaps a little bit of interaction.
(But then, maybe my idea of a beginner's level of ambition is hopelessly old-fashioned, I don't know.)
I do think that it would be great if there were a way to tell a web browser through its Dev-thingy to actually serve a folder to itself as if it were served by a bona-fide web server with HTTPS. I mean, it's not that hard to start a python-http-module-server, or install the npm module 'http-server' (or whatever it's called), but y'know...
EDIT: I don't necessarily disagree with you, but I think it may be a matter of degree.