[smallnamespace]

> It's a very serviceable compact serialization mechanism for at-rest data.

That's fair, but then you run into the same issue -- adding required a field requires updating your entire store.

Depending on your store, that can range from onerous to outright impossible.

> Don't do that without versioning your protocol

I think it depends on your needs, but I think for most users, explicit versioning of messages is overkill and is just a more heavy way of encoding the same logic (e.g. I saw an older message, I will implicitly upgrade it by filling in these new fields, vs. just looking for the optional field that I just added)