I also believe this is totally just a case of "billing and metering is hard, and may actually be a larger engineering effort than your actual service".
I was just looking at them earlier today since our Github actions are slow AF, and while they sounds great, this tells me it'll cost me more time to make sure I babysit it than most other trials.
With most of these, they end, the service stops working, and you have a choice to make: (a) it was worth it sign up, (b) not worth it revert.