Yea, I tried streaming for a while, and found exactly that. When I play some genre-specific stream with a goal of discovering new music, I find it's basically full of unremarkable, generic musak, punctuated by maybe 0.1% memorable, great tracks that I'm motivated to bookmark for later. Are these few needles worth slogging through hours of haystack? After a few years I have sadly concluded "no."
Not sure why this is. Has it always been this way (0.1% great stuff in a sea of mediocre?) or are "content creators" of today just more focused on churning out quantity than artists of the past?