True. But, how often do you fight foes with pack tactics?
As a DM and the more generic definition of pack tactics, I do it pretty regularly. I also am that DM who thinks that combined arms (aka I used ranged and melee guys, always) is the way to go. In 13th age, I LOVED using ranged guys who got bonuses when they had a friend within 5', and melee guys who could keep you within 5'

I think my current favorite monster has to be the simple skeletal archer, just for the fact they get ignored, you can use them
en masse without blowing your encounter budget, and do enough damage to really be a problem after a while without initially
looking like a problem

.
As for the specific example,
most pack tactics guys don't have range, and are Beast types. However, Thugs, Tribal Warriors, and Kobolds do. That, combined with bounded accuracy, makes them way tougher for way longer. Thugs and variants thereof are probably in the top 5 single most common opponents in many games.
Also, I should note, the guy they send in
does not have to have pack tactics.
I think it is a fringe case example, to be fair, but I think there is solid reason for it.