I am also in the camp believing they will sell ads the second they find a viable way (churn worth it, base infrastructure for it built, enough people trusting ai with product recommendations...)

I think the queries will fall into profitable (product recommendations) and non profitable (writing an essay or code) just the way they do for Google. Probably former will have a generous free tier and latter will be largely paywalled. I don't know how they'll do that, but I imagine they'll find some way

It's a mass consumer (software) product and they need new revenue venues and ads have a history of working well. Even Spotify, Netflix, Amazon Prime, ... Companies that historically don't have the ad infrastructure of Google or Facebook have increasingly profitable ad tiers