[dopamean]

Other commenters speculate that there is a technical reason why YouTube doesn't allow content producers to choose their monetization categories but I bet it's more likely to be a business reason. I'm sure it would be technically challenging and possibly for not much reward (for Google), however, I bet it's even harder to sell advertisers on ad packages that include Google ads when any producer can opt out of any group of ads. It would make it much harder to tell advertisers how many eyes their ads would actually make it in front of.

[dizzystar]

People would game the system. I do music, but everyone knows that other categories pay higher.

It also would depend on the audience you naturally attract. Attracting 19 year old girls will do better than 65 year old men.