You can ask yourself one question: Is there any chance you'll regret not having went on sooner?
Forget the benefits for a moment and think hard at where you want to be in 4-6 months, would you rather continue your growth now or then?
Up until hitting the wall I've been pretty happy. I've worked on interesting problems, enjoyed the work, had good co-workers mostly, lot's of freedom, felt like I've had a positive impact, and grown a lot. I've been on the lookout for next opportunities essentially since I started but really haven't found something I've wanted to do more. It's just that at this point it's pretty clear there isn't a long future.
Even if you can do a lot of stuff in css, sometimes you shouldn't do them. Razvan Caliman from Adobe has some good points on this topic: https://youtu.be/WupAsZGHDcY
Have you seen the whole presentation or just the first minutes? In the beginning he is showing some edge cases of css only usage, but then he actually demos some really good examples. The slides are here: