I have never found the need to use go-to definition, until I started working on some golang codebases. The code organization in these codebases is typically abysmal, with multiple files in the same package participating in N ways nested orgy.
Of course, micro is written in golang, and it seems like the author is doing just fine without relying on LSP.
If you've never needed to use go-to definition then I assume you never work on anything even remotely large. But even in projects with, I don't know, 10 files, I find go-to extremely useful.
Of course, micro is written in golang, and it seems like the author is doing just fine without relying on LSP.