You have to parse it anyway, and in either case (native or JS) you'll be using a pre-built facility for that. Plenty of "native" languages can have good JSON support these days, and the "create a wrapper for the API" part is trivial if there's one available already, even if it's JS.
In JS you can just access the fields. With a lot of APIs just being HTTP endpoints, call fetch, get JSON, see if you like how it works.
Move over to a better NPM library that wraps it later on if so desired.
But for prototyping stuff, JSON+JS is stupid fast. JSON store DBs suck for a lot of reasons, but getting something working in them is incredibly easy.
Getting that something to "real product" is probably end to end more work than if a better tech stack was chosen. You win some and you lose some!
For me?
Because every API I access returns JSON, and because half those API have a JS package sitting somewhere in NPM.
Bonus, a large % also have typescript definition files laying around.
So my choice is either:
1. Deal with JSON in native, and create my own wrappers for every API out there, because next to no one publishes C/C++ libraries anymore.
2. Give in to the JS behemoth.
tl;dr ecosystem.