1) I'm reasonably confident that this issue is not an accident. Better compatibility / better specs won't help here, I'm afraid.
2) A reference implementation for browser-features is an insanely complex project. Already there are effectively only two entities on the entire planet who can produce a browser that is reasonably close to the current spec. If you forced a reference implementation to exist, it'd probably just end up being Chrome(ium), which is arguably an even worse situation than where we are now.
It existed and was called Amaya.[1] Unfortunately it was way too expensive to keep it up to date with the ever-evolving specifications, and slowing down spec development was a non-starter. So it was canned.
WSYIWYG web editing seems to be impossible. CMS systems seem to have mostly given up on interactive HTML editors and switched to things like markdown.
I want to like Dreamweaver but whenever I try to use it there is a 1-2 sec delay between me typing text in and it appearing on the screen.
Most HTML editors behave like they are possessed by the devil: try to select the text in an <h1> and somehow it either selects everything but the first character or it selects all the text before the <h1> and also the <h1>.
A reference implementation isn't really enough either though. Think about Perl, which is implementation defined, vs Python, which is specification defined.
Python is much more successful (it really ate Perl's lunch), and less of a moving target, because of this. Alternate implementations of don't really exist, because they're always having to play catch-up. Python's specifications level the field a bit.
Things like browsers need some kind of open source reference implementation to act as a spec to maintain interoperability.
https://benoitessiambre.com/specification.html