Nothing that couldn't be automated; in Go land this is (arguably) called vendoring (https://go.dev/ref/mod#vendoring). Good to offload or reduce dependencies on 3rd party dependency hosters, pull a dependency into your own code review tools, and to ensure reproducible builds long term.

It's a generic and very old term for committing dependencies to your repo, it's not go-specific.

I mean there’s nothing stopping you from committing node_modules to git (after running something like https://github.com/timoxley/cruft on it) and reviewing code changes on dependency updates.

I even managed to make that part of the workflow on one team I worked with but several other teams since thought it was a crazy idea. :)