Using tailwind doesn't lead to any inherent concession of accessibility. How do you come to that conclusion?

If I look at their component library, they also do the work of including aria attributes for you https://tailwindcss.com/plus/ui-blocks/marketing/sections/pr... (first exsmple with free code I've found).

If we're not talking landing pages, which are more like digital brochures, I always start with markup and then add css classes on top.

Who said inherent. The design loop of “I need a div for my CSS class” is an ergonomic problem not a concession.