16 years of making content I was monetized just with donations, and to my surprise it did work to some extent, but the sheer amount of work it required to do was just ridiculous.
Over 16 years I just made around 2000€ from donations, these included direct deposit, not PayPal.
So to have a rough estimate on traffic and donations. It would approximately take 100000 YouTube views for 1 donation of 5-10€. You would make 1000€ from ads alone if your channel was monetized and you’d follow the guidelines, unfortunately my channel was not monetized.
The problem is that most people consuming your content are indifferent. They might enjoy your show and all that, but only handful of people will actually donate any money.
I didn’t get any grants to advertise my IBAN for free, so I relied on organic traffic from the content I created.
Donations could work if you’d be Wikipedia and push donations hard but if you just leave an IBAN or PayPal link on the sidebar of your blog, you wouldn’t get much because most people are in and out as soon as they milk you.