I've seen plenty of projects that made oodles of mocks and fakes and unit tests and just sucked, outright didn't work at all in a way that would've been obvious if they'd done testcontainers-based integration tests or even just manual testing in prod. I would absolutely trust a project that was written in Haskell and had no tests, or only integration tests, ahead of one that had lots of unit tests. Indeed if anything I'd say the number of mocks/fakes is negatively correlated with the actual project quality.