Their existing policy has never made sense to me. You can only give away so much stuff on a free plan. I don't think CI/CD is cheap. Buying extra minutes for $10 (not per month) is completely reasonable. At some point I feel uncomfortable using a free plan that is obviously unsustainable.
I think for CI/CD having a generous free tier is great because it makes it easier for people to get started and really dig into a project, not to mention the obvious benefit to open source that works as a continuous PR machine. Practically everyone knows what Travis CI and CircleCI are.
I still agree that it can be unnerving at times. I worry about services that seemingly offer no paid tiers. Like, draw.io. Thankfully draw.io actually seems to be sustainable, but you wouldn't guess it based on their very unobtrusive app!