I 100% agree with what you've written, but if you haven't checked it out, I'll highly suggest trying mockery v3 for mocks: https://vektra.github.io/mockery
It's generally faster than a build (no linking steps), regardless of the number of things to generate, because it loads types just once and generates everything needed from that. Wildly better than the go:generate based ones.
AFAICT that uses go/types, loaded uniquely per execution via packages.Load¹, which is by far the primary reason why e.g. go.uber.org/mock (previously github.com/golang/mock) can become extremely slow.
mockery v3 does not do this. it type-checks just once for ALL mocks, regardless of the number, so it essentially does not grow slower as you create more mocks (since type checking is usually FAR slower than producing the mock).
It's generally faster than a build (no linking steps), regardless of the number of things to generate, because it loads types just once and generates everything needed from that. Wildly better than the go:generate based ones.