As for the original question, I don't think that enamels are "out," so to speak, maybe just not as discussed.
It seems that most paint discussions I see are questions about how to get brand x acrylic to spray properly, or what should be added to brand y acrylic to work. So, with so many threads about acrylics in comparison to enamels, it might seem that this would be indicative of the death of enamels
As for me, I use acrylics exclusively for airbrushing, and a mix of enamels and acrylics for brushing, usually dictated by what color I need. If I have the color I want in enamel, that's what I will use first. If not, I will use acrylic. The primary reason I use acrylics, is due in large to ease of use (once the proper formula is figured out.) Ease of use in the ability to use it indoors without worrying about smells, it is easy to clean up, etc. Truth be told, if I had a dedicated work space separate from the house with a good booth setup, I would probably use enamels quite a bit more, if not for all my painting needs. I find enamels to be much less "fiddly" than acrylics, especially from brand to brand to brand.