From my perspective, I was paying for the model. This is kind of a pointless distinction now though.
It was working and now it isn't, and the outcome is that some of their customers are unhappy and might move on.
API access is not the same product offering as the subscription, so that's probably a practical option but not a comparable one.
you yourself admit that API access is a separate product. if you want to use 3rd party tooling, pay for API access.
if you want to use (most likely heavily) subsidized subscription plans, use their ecosystem.
it's that simple.