The big thing is JSON has common basic building blocks (simple types) so you are unlikely to see the same class of interop problems like SOAP and friends had ... "oh look this defines a new type my Python soap / xml lib doesnt natively support" (happened to me a few times, most memorable was akamai soap api using a custom list-of-string type nothing in python would parse out of the box)
However, it seems protobuffers (or alternatives like flatbuffers, cap'n proto) are still niches compared to JSON.
However I have yet to convince anyone at an org that isn't already using them that they will change things for the better.
Schema once, code everywhere. It is really nice.
Have you seen Buf? https://buf.build/
No, thanks for sharing! I will have a look!