The death of horn sections killed funk. It’s a complex music structure and modern music is simple. Also spawning off disco didn’t help it much. But in the end it was always a fringe type. There’s still some out there, Janelle Monae is doing some good funk. Plus of course the old farts are still cruising around.
You rarely heard funk on top 40 radio in the 70s or 80s. Maybe a white act like K.C. and the Sunshine Band. But a generation later everybody was sampling it. Hell, Snopp Dogg built an entire career off "Atomic Dog". I hope George Clinton got a taste of that ( but I'm sure he didn't).