I'd assume you would be able to publish and deploy locally before setting up actions. Such that those are likely targets in your build system?

Caching, I can mostly understand as unique there. Though, I think I'm living with whatever the default stuff in actions is. Slow for builds that don't happen often, of course, but not so slow that I care.

Unfortunately, my team has some builds that take ~25 min without caching and maybe 2 min with caching.

I'm still not entirely sure why it's the case, but the connection to the package registry is incredibly slow, so downloading all dependencies takes forever.

I'm fortunate that worrying about 25 minute builds just doesn't matter. The long pole on all builds is still the code review that goes with it, such that I just don't care about getting that time too low here.

That is, I am assuming that a CI build is not on the immediate dev loop, such that the person pushing it doesn't have to wait for the build before they prepare a review on it.

Why should caching in the cloud be any different than caching locally?

There isn’t any locally in GHA after the runner exits