I don't know if I got in me to write out a ton here--I probably owe this sort of thing a blog post or write up at some point--but I'll just say that marketing _really_ likes terms like "unlimited", sales loves to sell committed and contractual spend, and engineers love to automate (particularly in a PLG motion).
So you get things like...a lot of compute or bandwidth spend. (You know, I tried to think of other examples, but at some point it really does come back to the compute and bandwidth.)
And in a up-or-out kind of growth mentality, it's easy to handwave a lot of that away as just growth spending. But if the returns don't kick in big time at the end, you've just accelerated your runway.