It's not hard, but when you go from project A to B you'll have to check which formatter is used; this is additional setup / overhead, plus context switch. With Go, there is no additional setup / overhead / context switching, all Go code is formatted the same way with the same tools.

This is important when dealing with large code bases and many projects, it lowers the barrier to entry by a lot. A common anecdote from Go developers is how easy it is to drop into a random codebase and just be able to read/comprehend it and work in it right away, and the ecosystem-global code style is an important aspect of that.