Here's a thought: HTML does not separate structure, or content, from presentation. I'm not sure where the myth of the web's separation of concerns first arose - possibly from some architecture astronaut who'd never written an element in their life, perhaps from someone who really knew better but needed to slip something past the mediocrity police - but irrespective of what any non-normative reference may say, HTML does in practice blend structure, semantics, content, and presentation. CSS and JS substantially augment the presentation and semantics, but fighting against the grain of what HTML fundamentally embodies, instead of leaning on the framework, is a prime recipe for technical debt, not to mention opening the door for an awful lot of NIH.

Tailwind responds to that with an organising principle of styles refactored at the abstraction level of page components. It is not supplying an off-the-shelf design system for front-end novices a la bootstrap/material design. That is an excellent fit for a template-driven world, which is to say, most applications of scale. It is also an excellent fit for anyone (or any HTML generation language) that thinks of data as functional and anonymous. Naming things is hard, so the fewer things we're forced to name the better. My CSS has even improved from using Tailwind, not just thanks to the excellent docs but because it's been easy to experiment with alternative compositions.

To your specific inquiry - I've been maintaining several Tailwind frontends for a few years now, and it's been more reusable, more composable, and more maintainable that any of the hand-crafted CSS I might've written in the past, no matter how polished and proud I was of it.