We were talking about a variety of ranger abilities being used to set up an ambush, unleash a series of attacks over one turn and disappear, as opposed to any one ranger ability. The goal post had to shift quite a lot for the ranger to deal a load of damage even if all the conditions of the trick were met.
Ah, sorry I didn't understand the context.
Still, I'd question what you mean by "a load of damage"
A Rogue Assassin could attack from stealth and shoot a single orc for (I think lv 11 is 5d6 damage) 12d6 damage plus mod. You'd overkill the target easily, could even add poison to the arrow if you want. Then hide.
A Hunter Ranger could shoot approx. 10-13 orcs for 1d8 damage (using Volley), dealing approximately the same damage amount or higher than the rogue, just spread out over more targets. Then hide.
Next turn Rogue either runs because orcs charged the woods where the shot came from, or lines up a second sneak attack shot from hiding. Second shot if sneak attack probably kills a second orc. If the rogue flubbed the stealth roll then they deal only a d6 plus mod of damage and might be in trouble.
Next turn the Ranger would either run because the orcs charged the woods, or shoot volley again, or perhaps allow the orcs to charge him because he had set up a spiky growth spell or cordon of arrows spell before the orcs charged and he's leading them into a trap. Also, if he flubbed the stealth he can still do all this stuff. After getting another 1d8 each some of the orcs may start dropping (can't remember orc hp value) but all of them are pretty heavily hurt.
This doesn't require anything special, except a high level ranger to pull off the vanish move, which I agree is very high level considering the rogue gets it so early, but rogues are the masters of stealth and should be able to slip in and out sooner than any other class, especially since it effects their combat so heavily, while other classes do not need that level of stealth to be effective at what they are supposed to do. Still, I don't think the rogue assassin even at lv 17 has a good way to deal with +10 enemies at the same time. That is the current ranger's strength (again talking about the hunter ranger) they spread damage enough that they can handle being severely outnumbered better than any class that doesn't get fireball, and the damage they deal is good enough for 5e. They are effective, not flashy. Like the Fighter, who at best gets 8-9 attacks by level 20.