Highly intelligent people are most productive when they are tackling problems they enjoy. You cannot just order them around and tell them to go tackle climate change or whatever.
As long as they enjoy tackling crypto shaped problems, they will keep jumping in until enough crypto shaped problems are solved that only really frustrating ones are left.
If you want to change how things work, you have to change the environment for problem solving. Make it more or less enjoyable.
The compensation for working in those fields is often that you're working alongside other smart people, in a situation where your work is highly valued.
The money is just a factor in the equation, money equals respect in a lot of different ways.
People want to work on projects where meaningfulness and respect flows to them. Money is one of the things you want to see flowing.
Crypto offers that money, and offers a lot of technical challenges because programming distributed systems that must be error free is tricky.
In terms of the ad tech, a lot of the work on ad tech happens because Facebook/Google/et all have cultivated environments that offer that kind of respect, and offer serious technical problems.
Advertisements per se are not so much a part of it.