From the Author of emotion (css-in-js library).
Very wise words there.
I have huge respect for people like him that can put opinions in context and don't tell only a one sided story

Narrow down the problems you would like to solve and then ask yourself if CSS-in-JS is going to help you with those or avoid them altogether. Let’s pretend it will. Ok, now you’ve got a new set of problems you are going to learn how to solve and they are much more interesting than the problems that classical css presents, but you still have to learn how to deal with them. That takes time and energy that is precious in development cycles.

My larger point is to think about why we chose to use a library, framework, or pattern. Sometimes we create a problem for ourselves just so we can try something new. That is perfectly fine and its how we learn but just know that the context of that decision is everything. From my experience, the better route is to learn about this new thing and gain some understanding of the context of its use but do not force it but rather wait for a situation to arise when it is needed. Just be patient.