I suppose it depends on the size of the channel. If you have more subscribers than you can negotiate higher pay for in video ad placements. From channels that I have heard talk about it, google ads make up a minority of their revenue. Perhaps it is not the most representative example but Linus Tech Tips only made 26% of their revenue from YouTube AdSense in 2020.

https://youtu.be/-zt57TWkTF4?t=537