The 3d scanners create a point cloud which is then interpreted into 3d geometry with quality depending on the software used. Use case is very important.

Retopology may be required for specific use. Same for photogrammetry.

I've played around with cheap scanners and for still renders can give amazing results. Again it all depends on use case. The models would not be good candidates for animation, modding or 3d printing without retopologizing.