We use @apply to clarify the number of classes inside HTML and extract components.
I think TailwindCSS is here to stay for a long time. The main reason is that it's utility first. So basically you are using pure CSS but without writing CSS. It's very convenient and to be honest, I can't imagine using something else after I tried Tailwind.
I don't like CSS Frameworks (Bulma, Bootstrap, etc.) because with their popularity the web is becoming very similar. People aren't doing any design with them, just using the default components.
TailwindCSS made a very smart move here. They have components but they are very expensive so it won't be popular. Most of the people are going back to really designing things.
Never had problems with Tailwind set up. I use it with all my React, pure JS, and Ruby on Rails projects.