Even $6B is extremely far from the unprofitable claim.

Sales is, by definition, revenue. In this context, sales=revenue (although there is non-sales revenue, which is why the two words mean two different things).

I think you're getting at what is sometimes called "cost of revenue" and "net revenue" for businesses where it's important to report on sales channel costs.

Google doesn't break down the Play Store revenues this way, but for advertising there's a similar dynamic at play where it's "revenue" and "traffic acquisition costs"