This is always the thing to look for; "What are the alternatives?", and/why aren't there better ones.

I don't understand most use cases of protobufs, including ones that informed their design. I use it for ESP-hosted, to communicate between two MCUs. It is the highest-friction serialization protocol I've seen, and is not very byte-efficient.

Maybe something like the specialized serialization libraries (bincode, postcard etc) would be easier? But I suspect I'm missing something about the abstraction that applies to networked systems, beyond serialization.