You stated:

Quote Originally Posted by Bushwalker8 View Post
Given the accuracy topic, surface coordinates would then normally be transformed to local datum and coordinate system which is locked to the local land surface and relevant to it’s maps. This is intentional and the coordinates stay with the land and move with it and a point on the ground retains it’s coordinates in the local datum.
Then I asked:

Quote Originally Posted by babj615 View Post
How is that even possible?

Latitude is always parallel to the equator and perpendicular to longitude, which always extends from one pole to the other.

When California experiences 'The Big One' and Los Angeles slips several miles west into the Pacific ocean, you are suggesting that a waypoint I captured pre-event will somehow still retain the same coordinates after the event?

Ridiculous!
And your reply does not answer the question:

Quote Originally Posted by Bushwalker8 View Post
Only ridiculous if you are assuming accuracy and you or the device cannot manage it.
I still maintain that:

Quote Originally Posted by Bushwalker8 View Post
the coordinates stay with the land and move with it and a point on the ground retains it’s coordinates in the local datum.
...is not possible.

The distance between Phoenix and Los Angeles is a given value today, but after a large seismic event ('the Big One') where the San Andreas fault widens and pushes most of the California coast out into the Pacific ocean, the 'new' distance between Los Angeles and Phoenix will be much greater.

Any Latitude and Longitude reading taken at a landmark in Los Angeles prior to the seismic event will no longer relate to the same landmark after the event.

The coordinates do not change with the land movement.

Quote Originally Posted by Bushwalker8 View Post
Lat Lon is a projection, you don’t say what datum you are using.
Does not matter which projection or datum you choose. They are all man-made imaginary grids consisting of uniformly spaced parallel and perpendicular segments. The distance and bearing between any two locations in any projection/datum chosen will always be the same.

In the example I provided, at any point in time before the seismic event, the distance and bearing between Phoenix and Los Angeles had a static value, as would the distance and bearing between Phoenix and Dallas.

However, after the seismic event, the distance and bearing values between Phoenix and Los Angeles will have changed dramatically, while the distance and bearing between Phoenix and Dallas will have remained essentially unchanged.

There is no projection or datum that can account for this change in the Earths surface while maintaining identical before and after coordinates for all locations.

A GNSS user visitng landmark waypoints in each city that were saved prior to the seismic event would find the Dallas and Phoenix landmarks still located at the recorded coordinates, while the Los Angeles waypoint coordinates would no longer be anywhere near the landmark they originally referenced, but they would still be in the same location on Earth as when they were originally marked and saved.

Thus:

Quote Originally Posted by Bushwalker8 View Post
the coordinates stay with the land and move with it and a point on the ground retains it’s coordinates in the local datum.
Is not physically possible.