[SPBS]

https://www.sqlite.org/json1.html#interface_overview mentions that a binary encoding of JSON was experimented with, but no significant speedup or space savings were observed. If the functions are parsing and caching JSON that might explain why the performance is so close.

> SQLite does not (currently) support a binary encoding of JSON. Experiments have been unable to find a binary encoding that is significantly smaller or faster than a plain text encoding. (The present implementation parses JSON text at over 1 GB/s.) All JSON functions currently throw an error if any of their arguments are BLOBs because BLOBs are reserved for a future enhancement in which BLOBs will store the binary encoding for JSON.