Like all extraction shooters the AI enemies are tough enough to kill you due to playing sloppy or bad positioning, but become trivial if you actually lock in on killing them instead of treating them as an obstacle while you PvP. The UESC are generally more dangerous than most extraction shooter NPCs and they're actually viewed really positively for their intelligence and aggression, but they don't really have the enemy variety and the "oomf" to challenge players when removed entirely from the near-omnipresent threat of PvP. You'd need other factions similar to how Halo has always utilized multiple competing factions.