That's true, but not for media queries or pseudo selectors. I suppose with CSS custom properties it would work something like this (please correct me if you know a terser way to use defined colours and weights):
<span style="color: var(--color-primary); font-weight: var(--weight-extrabold);">my text in primary color and extrabold</span>
I believe Tailwind's syntax is still far terser and more manageable:
<span class="text-primary font-extrabold">my text in primary color and extrabold</span>
When you have lots and lots of styling this quickly becomes important
OK, but my assumption was that this syntax was proposed as an incentive to use Tailwind, rather than trying to cram custom properties into style attributes.
If I’m going to use custom properties it would be in a way that plays to CSS’s strengths.