I think it is very unlikely that they are charging less money for tokens than it costs them to serve those tokens.

If they are then they're in trouble, because the more paying customers they get the more money they lose!

Operating at a loss to buy market share is pretty much the norm at this point. Look behind the curtain at any “unicorn” for the past 3 decades and you’ll see VCs propping up losses until the general population has grown too dependent on the service to walk away when the pricing catches up to reality.

I guess that depends on the user; most people are not getting most out of flat priced subscriptions. Over all they probably make a profit, and definitely on API use, but some will just spend a lot more. It'll get cheaper though; they are still acquiring as long as there is VC money.