[simne]

You are very close to truth.

In reality, analog precision is not scaled.

Really easy achieve 8-10 bits, even 12 bits, but 16 bits or more are hard.

For example, now manufacturers use large matrices with lot of spare parts, and before put chip in case, it's precision measured and cut metal seals, so made very precise parameters.

So in reality, modern analog chips ARE one time programmable analog, but one time analog programming is cheap enough but rewritable are inadequate expensive.