I dunno. Based on my own viewing experience with most YTs, there’s an awful lot of ‘something’ going on. I rarely see anything anymore that’s a ‘straight-to-the-point’ video with no ad promos. Regardless of how you cut it, sponsored by ad revenue is a form of monetization and those agreements aren’t always clear about what ‘tit’ is for ‘tat.’
And then there are the vlogs that pretty shamelessly hawk their wares for anything from subscriptions, donations, visits to merchandise links, investments and anything else that could derive funding.
Yeah, there’s a lot of “something” going on. This explains the process:
https://www.wikihow.com/Become-a-YouTube-Partner
This is why channels constantly badger you to subscribe.
There are major restrictions on eligible content, so if your material is not in line with YouTube biases, you can forget about getting money from YT, and if you’re lucky, they won’t kick you off the platform.
Many resort to side hustles to make money (e.g. $20 coffee mugs, $60 hoodies), but this says nothing about whether the channel is monetized or not.