D&D 5E (2014) High Level Monsters and Magic (or not)

[Zaukrie]

When looking thru the various monster books, I noticed that pretty much no high level monsters have magical attacks (when looking at their "weapon attacks". Their weapons and natural attacks are not magical in nature. Also, a lot of high level creatures, or even non-natural ones, have damage resistance. Do these monsters just fight each other for twice as long as everyone else? Do people assume that a high level Drow has magical weapons (like any PC would)? Is the Balor really carrying a non-magical sword (I note that angels, for example, have magical swords)?

thanks (and I figure that has been discussed already, or I'm missing a rule, or 5e is just different than I expect)

 

[Yardiff]

Magic Weapons. The balor's weapon attacks are magical.

 

[Yardiff]

Drow Magic.] ust as the drow have adapted to
underground life, so too has their magic. In addition to
using that magic to carve their cities from stone, they
empower their weapons, create dangerous new magic
items, and summon demons from the Abyss. Drow
spellcasters are supremely arrogant and never hesitate
to use their magic in the most abhorrent ways.

VARIANT: DROW MAGIC ARMOR AND WEAPONS
Drow often wear magic armor and carry magic weapons that
lose their enhancement bonuses permanently if they are
exposed to sunlight for 1 hour or longer.
A drow wearing a +7 chain shirt and carrying a+ 7
shortsword has AC 19 and a + 1 bonus on attack and damage
rolls with shortsword attacks.
A drow elite warrior wearing +2 studded leather and carrying
a +2 shortsword has AC 20 and a +2 bonus on attack and
, damage rolls with shortsword attacks.
A drow priestess oflolth wearing +3 scale mail has AC 19.

 

[MechaTarrasque]

The monster manual monsters are just the ones that PC's get into fights with. The legions of Hell don't waste magic weapons on devils sent to the mortal worlds, they save them for the Blood War. If demons that regularly cast 9th level spells showed up on a campaign world, everyone there would have their brains leak out through their ears (just think of what kind of 9th level spell unknown to mortals that demons spend millennia developing, leaking brains might be on the tame side.....).

Monsters that are likely to be summoned are a different story (and remember that only clerics could summon fiends using spells from the PHB, so not much need for them to have magic weapons, since evil clerics could beg for fallen celestials with magic melee attacks). There does seem to be a 7th level gate to getting monsters with magic weapons via summoning (most critters available for conjure celestial and at 7th level you can get elemental myrmidons whose attacks are considered magical for purposes of overcoming resistances and immunities from conjure elemental).