Agree. As an example, this proto generates 584 lines of C++, links to 173k lines of dependencies, and generates a 21Kb object file, even before adding grpc:

syntax = "proto3"; message LonLat { float lon = 1; float lat = 2; }

Looking through the generated headers, they are full of autogenerated slop with loads of dependencies, all to read a struct with 2 primitive fields. For a real monorepo, this adds up quickly.