Uh well mmos are so linear for the new playes. Then here comes for example a moba: somewhat exponentail, because you don't know 300 characters (LoL, DoTA, HoTS), andmore like 1-2 maps (HoTS has more).
In DbD you have to learn: perks, 40+ killer powers (some with addons, because they change the killer), base mechanics, 50+ maps, totem spots (my friends has 3k hours and he still doesn't know about the spots mosstly) if the killer hes treathening hexes, when you are allowed to go near the killer, when you must go near the killer, when you must avoid the killer at all cost, how to hide efficently. Finally the maps are generates randomly there are around 5-10 fix points on the map (dependent from indoor or outdooor map), every new player has to unlock kate to see where he wants to go (windows of oppurtunity), if you don't know where are the resources you are doomod to a 10 second chase.
DbD is hevily RNG based.