From my understanding (not a vlogger, not a streamer), it may be safe to buy music from content platforms[0] but generally music is tricky business: no matter what you use, you are risking some YouTube music ID bug or frivolous DMCA takedown shutting down your channel at any moment.
Even if you have gotten a green light from the original musician, go prove this to a giant corporation that will never have a human representative speak to you. (Stories about people publishing their own music on YouTube only to get it taken down due to a false positive were posted even on HN, I believe.)
Thus, creators seem to use either 1) no music at all, 2) their own music, or 3) generic-sounding music from some royalty-free content platform.
I am wondering whether Bandcamp will finally do the next logical thing and streamline the process of licensing music for video creators directly from musicians (those who opted in).
[0] For obvious reasons, few good musicians are willing to publish music on those royalty-free commoditized music farms.