If the thing the beacon is attached to moves the co-ordinates would need to update and would not be of use because its just GPS. Static beacons are useful where GPS resolution isn't great (concrete canyons), in buildings/structures or an area where theres a high density of beacons that GPS can't resolve quickly or finely enough.

A beacon represents a thing and not a fixed location. A beacon on a vehicle would say "hi I'm vehicle ABC123…" rather than trying to find that vehicle by 2D geospatial resolve from a GPS fix referencing a known database of last locations of vehicles.