3d scanners are amazing - as long as you have very deep pockets indeed.

The 'cheap' ones aimed at hobby 3d print enthusiasts, are largely - useless for anything requiring proper accuracy.

The industrial ones, on the other hand are ansolutely amazing, and start at around £20,000.

I've bought a few cheap scanners over the years, and they are a complete waste of money.

I can generally replicate a part with digital calipers and openscad much faster than scanning, and with complete accuracy.

But if you have the money .....
Then your ocean really is full of oysters !