I know it’s slower absorbing, but if you take more you’ll reach the same level as whey, and stay elevated for several hours longer. I do think it’s a little lower in leucine, but aside from that I feel like it can be beneficial. I’ve been using it more than whey lately.
They each have their own uses but yes casein is definitely much less popular and the avg person doesn’t know about it. Personally I take whey post workout and will take some casein with breakfast if I don’t have a high protein meal and before bed most days to top up my protein intake for the day.