Rapidata answered this in another comment below. They integrate micro-surveys into mobile apps (like Duolingo, games, etc) as an optional opt-in instead of watching ads. The users are vetted and there's no incentive to answer correctly.
Answering correctly is not in question here. This is essentially opinion polling anyway, there is no single correct answer.
The incentive is exactly what you said: to skip ads.
How are the users actually vetted? We have no information on this, just have to take rapidata on faith.
I think we all mostly agree that there is a single correct answer, and that is why this discussion exists in the first place.