Sounded like buying indulgences to me.

"My sins are forgiven as long as I tithe some of my profits". Buys your way out of the issue, doesn't change the lifestyle.

He'd have more take-home income if he worked outside of ad-tech and didn't give 50% of income to charity. So from a utilitarian perspective, I think I'm basically fine with this? Even if ads are "evil" (I am skeptical), they are very much a first-world problem compared with major global problems like malaria, clean drinking water, and hygienic bathrooms.

The trick to the utilitarian calculation is to include the externalities of all the work he's putting in -- an engineer's salary is only a subset of the value they create for the company.

The question is really how do you count all that excess "value", and is it good-value or evil-value. Once upon a time, the culture over there explicitly stated that they didn't want it to be evil... the bikeshedding going on here is opinions about the current implications of it all.

The advertising industry is bad enough that it's not necessary to exaggerate by saying things like "dominates the entire world". Unless you do indeed mean that, in which case, how do you define it?

Yes, and in this he contradicts himself because that statement is a tacit admission of the ethical problems, yet the rest is basically a justification of all of it.