Not everything is at scale. We have adopted these techniques (at the beginning of this year) for our internal web frontend to our build system at work and it makes it possible for all of the team to work on this system without having to setup a complex node environment or deal with npm. We also get the pretty shiny that Tailwind brings to the table. Our system is as simple as can be but not any simpler.
I don't consider Tailwind (or any atomic CSS library) "as simple as can be". Having to know a bunch of custom naming conventions seems to go against this whole idea.