It's easy to view the bugbear as just big strong goblins, with a bunch of hit points and the ability to hit like a truck. But that would be a shame because this thing is literally the boogeyman. Sure, they are brutes and the extra damage die their rolling every time the hit is pretty scary to low level PCs, but despite their bulk they are also light on their feet: very sneaky with a +6 to stealth and their surprise attack feature. If the bugbear gets the drop on a PC that's an extra 2d6. An average of 18 points of damage is going to permanently kill a lot of level one characters, no death saving throws, just dead and they didn't even see it coming.
Now, I'm not saying that you should do that to your players but you can let them know this thing is out there stalking the night and make them fear it without killing a PC. I might have an NPC, even a stronger, mentor-type character maybe lead the party out there and then take a crit from a bug bear waiting in ambush and boom 36 points of damage later from this fury monstrosity swinging a morning star and I think the players might get the message. Now that's a monster. Plus now the party has got some real motivation.
There is a lot of solid info and lore in Volo's but the Monster Manual in a few quick sentences gives us a full picture we can use to roleplay and make a fleshed out creature the players can interact with in various, interesting ways. The bugbear flees when outmatched, but can also be persuaded and even hired on with food, drink, and treasure of course. You can't count on them to lay down their lives for you, but with their solid survival skill they'll make good wilderness guides and trackers, let alone hired muscle.
In one of my settings I've got a little old lady setting out a plate on the back porch each night for the bugbear who lives in the woods down by the creek, and so he watches over her homestead and keeps the woods clear of nasty stuff. When she passes the now-hungry bugbear starts making trouble around town, and if the adventurers dispatch this persuadable fury boogey man, the things it was keeping at bay move into the vacuum and pose a real threat now.
I'm not telling you you've got to run things this way. Of course if you like my ideas steal them, I mean, adapt them with my blessings. But these are the kinds of questions a good DM is going to consider outside of a session. What makes a bugbear different than a hobgoblin, and what makes this bugbear different than the last one. Sure, sometimes you just want cannon fodder, but I really get a lot of enjoyment out of these world building considerations. If you want some really well thought ideas, at least on the combat side of the equation, I can't recommend The Monsters Know What They're Doing enough. The blog is great, and the book is even better.
