It is far harder to get traction to reach their scale than to make money from your users when you have so many. They explicitly are focusing on growth.
Also focusing on user engagement, as they are narrowing down on solving needs that are a) painful and b) frequent. They want users they've already attracted to be firing up the app daily, not weekly or monthly.
User retention is probably the biggest problem they have now and if that is not squared away, no way can they ever monetize or be profitable.