If you're not running a multi-million $ site, you're especially screwed for alternatives unless you're selling something and can get affiliate revenue.

If Bob wants to put up a video fixing vintage washing machines, he'll have to do it out of 100% altruism, because Google is going to take all the ad revenue.

Google have a fair number of monopolies. Just not using Google products is obviously not a viable option in many situations.

(Not that I recommend using it. I recommend the old fashioned ways of knowing where your banner ends up. And make sure it doesn't become one of 344 on some random site. So build partnerships, etc. Yeah, it sucks, it's work.)