Yeah that's why I skip it. It's to keep things moving. Death saves for enemy NPCs only crops up for me when the enemy is particularly important, or the enemy force has healing capabilities - they can Healing Word a downed person just as much as the players can.
Strictly, the streamlining does make it easier on players than giving death saves to everyone all the time. The chance of a nat 20, and having to spend attacks/actions to finish them would give those still standing more turns to live.
But if I want things to be more dangerous it's probably easier to just toss another dice of damage on every creature than do death saves.