People think of D&D as being the most generic of generic fantasy, a sort of baseline fantasy default but in actuality D&D is this weirdly extremely specific thing where in many cases entire mechanics or setting pillars are all derived from one guy. Like for example, the entire idea of rangers dual wielding weapons is derived from one wildly popular tie-in novel character, up to the point where in 5e the rules were subtly changed to make it easier specifically to dual wield scimitars (something that the 3e rules made weirdly awkward)
The cleric basically only exists because someone in Dave Arneson’s game wanted to play a vampire hunter
which, it should be noted, only happened because a DIFFERENT guy was playing a vampire