I am not sure. There are already superior (IMHO) alternatives and JSON still sticks around unaffected. For instance, at work we use protobuffers everywhere and now I am so used to that that I started using them also on my personal projects since I believe they are so convenient. In fact, I am not sure how many hours I saved from not having to write serialisation/deserialisation code, and how you can get full IDE support for your messages.

However, it seems protobuffers (or alternatives like flatbuffers, cap'n proto) are still niches compared to JSON.