Snapping ‘On entity’ is for a perfect nearby coordinate on the entity.
It is expected to work for all supported shapes.
A screen has but a limited number of pixels in a certain dpi.
It would be impossible to point to the exact location on some vector art with the cursor in any (deep) zoom level.
For that ‘Snapping’ to a nearby exact coordinate is an essential tool.
That can range from ‘Free’ (No snapping) to the distance intersection of 2 entities.
And some restrictions can be activated, see menu Snap.
These are also shown at the left when a coordinate input is required.
Typically ‘Auto Snap’ is active what is an hierarchical mix of all nearby positions.
You must point nearby the intended, ‘Auto Snap’ may revert to the nearby Grid point.
‘Auto Snap’ is configurable.
Regards,
CVH