I leveled a troll warlock 1-120 last weekend, took me 30 hours 45 min on /played, i went afk a couple of times so let’s say about 30 hours, i was using heirlooms (no heirloom rings or xp gems), warmode on, draught of ten lands and the event 15% buff.
1-10 I just did quests at the initial area.
10-60 I asked a mage for a portal to vale of eternal blossoms, travelled to valley of the four winds and kept doing pet battles against critters there.
60-90 I started joining korrak but kept doing pet battles while i waited for queue.
90-101 I went to draenor and leveled through treasures and map objectives, while there i kept using Excess Potion of Accelerated Learning.
101-110 I did korrak and since there was a legion invasion up at the time i did that too.
110-120 I did korrak and bfa’s war campaign while waiting for queue, i didnt join queues as a mercenary because i wanted to unlock the boat shortcuts to each kul tiran map.
I have all pathfinders unlocked and at early levels i used Spellstone Delight to travel.
I want to level my LFD (21) but leveling feels moot at this point.
Depends how serious you are playing the game, and if doing dungeons how serious those people are. Some people are like non stop machines some people are far more relaxed. Some good estimates posted.