A phone can sometimes put you very close to the correct point and at other times draw a wandering trail across nearby buildings. Both outcomes can come from the same handset. GPS accuracy is a measurement with conditions, not a permanent specification.
Satellite geometry, signal strength, atmospheric conditions, antenna design, nearby structures and the algorithms combining multiple sensors all affect a fix. A result obtained in an open field should not be used as a promise for a railway station, office tower or underground car park.
Applications also receive an accuracy estimate with location data. That estimate is more informative than publishing one marketing number for every phone model.
Outdoors with a wide view of the sky, the phone can receive signals from many navigation satellites with relatively little obstruction. That generally produces more stable positioning.
Turn the same phone sideways between tall reflective buildings and signals may arrive indirectly after bouncing from walls. The calculated point can shift substantially even though you are standing still.
Android allows users to grant approximate rather than precise location to applications. An app that only receives approximate access should not claim that it can provide precise GPS tracking.
For a tracking application whose core purpose is to record an exact route, the permission state therefore matters as much as the hardware.
A route line connects successive observations. Small position errors that alternate left and right can turn into a visible zigzag. If the device is stationary indoors, noise can create a scribble that looks like movement.
That behaviour is covered in more detail in Why is my phone location wrong? and GPS indoors and in urban canyons.
A real test on your actual device is more meaningful than a generic accuracy claim attached to a model name.
Location APIs can provide an estimated horizontal accuracy for a reported position. It is better to think of that as an uncertainty radius than as a guarantee that the phone is exactly on the marker. A smaller reported uncertainty generally gives you more confidence than a very large one, but it is still an estimate produced under real radio conditions.
For a tracker, storing or displaying that accuracy alongside the timestamp can help explain odd points. A route point recorded outdoors with tight uncertainty and a point recorded deep inside a station with broad uncertainty should not be interpreted with equal confidence.
Accuracy is also separate from freshness. A precise point that is ten minutes old may be less useful for live tracking than a slightly less precise point captured a few seconds ago.
Different phones use different antennas, chipsets, power-management policies and sensor-fusion implementations. The way a person carries the phone can also affect reception: a handset held in the open is not in the same radio environment as one buried in a bag beside other electronics.
Software matters too. One application may display a cached position immediately while another waits for a newer fix. One may smooth a route heavily; another may show nearly every raw update. Comparing two map dots therefore does not isolate the GPS hardware unless you also compare timestamps, accuracy estimates and test conditions.
For a meaningful device comparison, use the same outdoor route, similar settings and enough time for both phones to settle.
The answer depends on the use case. For remembering which motorway or hiking trail you followed, a route that is occasionally several metres off may be perfectly useful. For deciding which entrance of a large building somebody used, the same uncertainty may be too large. Consumer phone GPS should not be treated as a surveying instrument.
When LocationOf is used for family coordination or travel logging, look for the broader pattern across several points instead of treating one marker as absolute proof. Indoors and between tall buildings, uncertainty can increase dramatically because of blocked and reflected signals.
See GPS indoors and between tall buildings and why phone location can be wrong.