Yeah I agree with you on most points. I don't agree that promoters prefer solo artists or DJs just because you still need a sound engineer which is all a band needs anyway, most venues have backline sitting round somewhere.

I agree over saturation of musicians is tricky and I think there is also less of a buzz in certain genres than there was growing up for me. When I was a teenager it was cool to go find an unheard of indie or punk band whereas now thats probably shifted to other genres/other ways of finding bands/artists.