I don't think of it as an alternative to CSS. I think of it as a way of writing CSS.
It can get long. I certainly have parts of my app where I break out into plain CSS because it's easier to understand.
I put most of my Tailwind utilities on their own line in my HTML, and for elements that need more than 3 or 5, I do the same but in classes or styled components where I'm listing them off instead.
Keeps everything clean and readable!
I'm often in a cycle where I am tweaking a complex class with 10-20 properties including flex, transforms, animations, etc. - and having them each be on their own line (and the class being in a separate file along with its parents, siblings and children, frankly) is key for readability to me.
I guess in the end I have come to have enormous respect for CSS as a powerful, mature language and I'm not looking to be buffered from it.