@Flamestrike
What poundage is the bow the girl is using. Definitely not the same as a medieval war bow which is what the game is modeled on.
What the hell is a 'medieval war bow'?
The girl and guy above are using composite bows, common in ancient Persia, among the Mongols, Scaracens and elsewhere for the last 2000+ years.
'Draw, nock, aim, fire' isnt exactly a time consuming process.
As for a longbow:
That guy above is easily firing a dozen+ arrows per minute, and he's using a longbow (the slowest manual bow of all). He could double that fire rate with training and experience (he's not exactly racing to get his shots off above).
Bear in mind these guys and gals are just normal guys and girls with some training; they are nott Achillies-esque near mytholgical warriors of legend as represented by the Fighter class.
Remember; a Fighter, Barbarian or Ranger can pretty reliably kill a Grizzly bear from around 3rd level onwards, with nothing more than his bare hands. From 5th level, they're all but assured of victory.
Your average BM fighter has Str 18 at 5th level, dealing 5 damage per punch, plus a superiority dice. He Action surges on turn one, attacks 4 times at +7 (vs AC 11), likely dealing 4d8+20 damage, and
bludgeoning a Grizzly to death with his bare hands inside of a few seconds. If he has the Tavern Brawler feat or the Unarmed combat fighting style from UA, the Bear is even more screwed.
If the guys and girls in the videos above an fire a bow that fast, then Achillies, William Tell, Cu Culain and similar legendary warriors (i.e. the Fighter) can do it even faster.