the same could be said for languages that aren’t binary: what does it save you! you still have to write stuff to get the program you want, and you still have to come up with the business rules

almost all software engineering tools just save you keystrokes, or save you from needing the knowledge to implement repeatable things… or for having a standardised way of doing things so new people can approach your project without having to learn as many details (eg rails, django, nextjs, etc: the terminology and layout of such projects are familiar; daos/views/etc all behave the same)

for css frameworks for example, perhaps you have a .rounded-corners class… sure you could just implement it yourself, but if you’re using a framework you save a few minutes, the outcome is likely the same, you don’t need to know about the border radius details (and likely css frameworks implement things like shims or accessibility correctly; freeing you from needing to have deep knowledge of some esoteric details), and if the framework is big (like tailwind etc) then if you employ someone new, they know exactly what .rounded-corners means

… obviously .rounded-corners is a pretty simple example, but you can imagine when these libraries fill out with many many tools the shorthand’s get much more complex

Some (many) people find it easier to learn a small number of predefined class names that accomplish what they want without having to know hundreds of different CSS incantations when they're just trying to make a simple site.

Sorta like how people use a command-line instead of just writing the code themselves.

I am primarily an embedded software engineer. However every now and again I have to write small web apps, having a CSS framework allows me to style it with pre-made classes saving me a boatload of work and learning and having the result look good.

A CSS framework allows you to not write any CSS! You just add utility classes to your html. I personally use tailwind and I guess there's some advanced stuff where you'd have to still write CSS yourself but for most use cases it's a lot easier. Flex layouts, notably, are a breeze.