That’s actually quite accurate! To answer your concerns, for (single phase) AC like in many outlets, ground (the reference voltage) is most convenient to be the same as earth (0V). For this reason calling earth “ground” is fine, as more often than not it’s both earth and ground.

Just to add, any voltage you use often in a circuit as a reference (say for comparators for example) is called a reference ground. So if you split 0 to 5 V in half, and keep using 2.5 V for various comparison purposes, the 2.5 V could be called a reference ground.