Yes, I did use SASS before Tailwind (and Compass back in the day), and got a lot of value from them. Where it started to get painful is when I have:

    a.link {
    
    }

    a.another {

    }

    <a class="another link">...</a>

It was easy to fix, but hard to scale the fixes over different codebases, timelines, and developers. That's the problem Tailwind solves for me.

CSS nesting will be available to us mortals (in production) within a year and we might be able to use it just a guess as early as 2026?

https://webkit.org/blog/13813/try-css-nesting-today-in-safar...

That misses the point. This is still worse than seeing all your styles in the place where they apply. SASS/LESS just make it faster and more succinct to write styles in css files rather than in the components in which they live and even more importantly—on the actual ELEMENTS that they apply to.

Fallen out of favor with who?