@bjacobse With two extruders you load up each with your most common filaments and thus do a filament change less frequent. Then it is a "nice-to-have" but nothing cruicial at least not for me who rarely combine materials in same print.
In more advanced use when people want to print for example support structures in one material and the item itself with another filament this is not practically possible with less than two extruders.
Changing colors can be done with one extruder but frequent changes for same part are of course a pain.
So depending on use the dual (or even more complex) extruders are everything from just nice to a must. For a beginner it is not needed (and for something "home built" it is most likely possible to change to a more complex extruder after some years).