Understandable for when lets say a book claims there’s a castle but ingame all you see is a tent and campfire, but this isn’t a case of a book claiming there’s a castle where you in game seeing there’s a tent.
Nowhere in the blood elf starting quest zone is it implied that Blood Elves, or your player character even, consumes fel. One of the quests in the starting zone is even about teaching you mana management through manatap and arcane torrent so you can fend for yourself in a post sunwell world (until it got repaired, which was a shame, belves are cooler without a sunwell, I hope it gets blown up in midnight again). Manatap to claim the mana from your surroundings and arcane torrent to discharge to prevent going wretched from overconsumption of mana
Its an undisputed trace of them being exposed to fel magic
Consumption leads to what you’d see in the felblood elves of Outland, the ones hardly distinguishable from demons so to say.
I can counter that as easily by saying its lame to expect other people to do your research for you and arrogant to expect you can treat people a if they’re your secretary, but fine for the sake of arguement consider this a freeby:
There were two main reasons, one reason is, the blood elves actually couldn’t hold the tide against the undead, The forsaken, lead by former ranger general Sylvanas were sent to Quel’thalas to help stem the tide, without those forsaken the Blood Elves would not have made it. This is also one of the main reasons why they joined the Horde, Sylvanas outright told them join the horde or you lose my support and that would’ve meant the end of the blood elves.
The second reason was them regaining the ability to wield the light again through a captured naaru called M’uru, Magisters drained the Naaru of light and bestowed it on those who could wield it in combat. The Blood Knights under the lead of Liadrin were founded shortly after iirc and they wielded the stolen light of the Naaru. They also did a lot of questionable things you wouldn’t expect from conventional paladins (the blood knight master quest which gave you the tabard and epic mount was literally go burn the church in stratholme to prove we’re better at wielding the light then the alliance paladins are)
Wielding stolen light is different then wielding true light, though. It seemed harmful for its wielders to wield (which was the explanation to the original blood elf paladin exclusive seal of Blood added extra damage to attacks at the cost of HP of the paladin). This regaining of the light also allowed them to fight back much more efficiently against the undead.
These two reasons are the main contributors to Quel’thalas not being overrun by scourge and unless you were a warlock you were not consuming fel.
Unless an elf was part of an actual class that wielded Fel (warlocks mostly, maybe the occasional blood mage but the only overlap they really have with warlocks is destructive fire magic, not fel)
Edit:
Also, as Lorcathar/Erevien stated, the split between high elf and blood elf happened before Kael’thas went to outland to even discover fel as an alternative option, Fel has nothing to do with it again.
Kael’thas tried to rename their people to the Blood Elves to honour the loss of their bretheren to the Scourge. The High Elves that didn’t go along with this and remained high elves did so for varying reasons but by and large because they felt Kael’thas had failed them, as he was absent during the scourge invasion, he was in Dalaran either for diplomacy or studying magic I don’t remember the why exactly and this also happens before the warcraft 3 campaign of KT in which he is informed of fel as an alternative by Illidan.
