I don't agree.

Protobuf works best if you have a monorepo. If each of your services lives within it's own repo then upgrades to one repo can be merged onto the main branch that potentially breaks things in other repos. Protobuf cannot check for this.

Second the other safety check protobuf uses is backwards compatibility. But that's a arbitrary restriction right? It's better to not even have to worry about backwards compatability at all then it is to maintain it.

Categorically these problems don't even exist in the monolith world. I'm not taking a side in the monolith vs. microservices debate. All I'm saying is for this aspect monoliths are categorically better.