I don't agree. I want to be clear that I think youtube is terrible in many, many ways, but one thing I _do_ love about youtube is music discovery. Finding label channels and tracing through their artists, seeing what else pops up in my feed as a result and following those threads...finding random weird stuff with four listens posted two days ago, which then leads you to more weirdness...etc. is all very fun to me and I've discovered a ton of great music that way. There's also tons of random channels that have DJs or mixes they put out that is also a great and relatively organic way to discover new stuff (I'm always thrilled when a new Kieran Hebden set drops on The Lot Radio for one).
Maybe spotify is different, I've actually never used it, but I don't think the "Thrill of the Hunt" is dead in a general sense. And I'm kinda old, I was a music major in the 90s and at that time I was all about finding weird bootlegs and going to shows with <10 people showing up, subscribed to The Wire for a long time, and etc. There is still a ton of great new music out there and fun avenues for discovery! If anything there is more than I ever could have imagined when I was younger. People keep making great stuff.