GPS + a topo map yelling at you for being too close to the ground is extremely simple, a very basic feature.
Dead reckoning (keeping track of position over time without an external source of truth) and radar altimeters are high level features that some avionics do have, but these are expensive and not expected to always be present.
Inertial navigation systems you'd find on missiles are precise enough that if you leave one running on a table in the upper floor of the building you can track the rise and fall of the building as it heats up and grows because of thermal expansion throughout the day (in other words, they are extremely precise).
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GPS + a topo map yelling at you for being too close to the ground is extremely simple, a very basic feature.
Dead reckoning (keeping track of position over time without an external source of truth) and radar altimeters are high level features that some avionics do have, but these are expensive and not expected to always be present.
Inertial navigation systems you'd find on missiles are precise enough that if you leave one running on a table in the upper floor of the building you can track the rise and fall of the building as it heats up and grows because of thermal expansion throughout the day (in other words, they are extremely precise).
So it depends.