I tend to agree here, judiciously used json (these days often running under zstd compression) is seldomly the bottleneck on anything and allows immediate human debugging if need be.
What we actually implement is often more constrained by what we can prototype and experiment on than how fast or how well we can define formal requirements and implement them.
So much good stuff in software is down to a mix of serendipity and 'what if' and anything that reduces friction (improves ergonomics) has my vote.
