outside of Q, I think I've used most all of these in one way or another for various reasons. Most can be done with calc() and whatever the nearest root value is - but some of them are handy, even if they don't appear so.
i, for one, am most looking forward to full support of subgrid - pure css masonry/isotope layouts with no JS needed when your cell requires images to retain a certain aspect ratio, as well as span multiple rows/columns, but has accompanying text that can vary in height. am aware that's a very specific thing, but will be nice to not need a JS crutch for height calculation
hate replying to something i already did - but i also never said liveview required JS, just...it still uses it if there. Liveview is a really slick answer to this whole thing, and I recommend readers of the thread to check out. And now I have nothing.
i think you're conflating static sites with sites that lean heavily into JS frameworks. plenty of sites are not static, cause they need that whole session thing, and don't use JS frameworks
realistically speaking, if done correctly - SSR would allow the site to work without JS. Now, in practice, that comes down to what is required on the client side for interactivity - which is a case by case basis, and if your site doesn't require JS on the FE at all, why would you use it for the backend
and when websites are kind of apps, but not really so you need the SEO benefits of regular websites yet the interaction of apps....then you get into the fun bits
been a juggling act for me for some time, and always comes down to - they'd rather take a performance hit vs. harm the branding/interactivity. tho we're in a very niche market that doesn't seem to mind (i do my best to make it as efficient as can be)