The original motivation of CSS was the
cascading aspect of it. During its development, the web was largely seen as a web of documents. Style sheets tried mimicking how traditional publishers style their documents, books, etc. There is also a need to reconcile document styling applied by the user agent, the site author, and possibly other sources. This is where cascading comes into play.
Problems start to occur when using a system designed around traditional publishing to declare the layout of a web application. This is why CSS eventually gained layout-related functionality (flex, grid, container queries, etc.), among other features.
Tailwind provides two things out-of-the-box that make it convenient for building web applications: (1) it comes with a ready-to-use style system; (2) it allows styles to be colocated with markup. The second point is mostly useful for building UI components. Everything strictly related to presentation can be stored within a single file.
Before using Tailwind, I was a strong advocate of CSS modules (and I still strongly advocate for CSS modules if one wants to avoid Tailwind). With either approach, one can achieve isolated styling between components. Repeated styling or markup is a strong indicator that you should extract something into a component.