Very well aware of that. I loved the Berserker class from the 2E "Complete Viking" book. One of my favorite characters, ever.
That's not what the 5E Barbarian (or the 3E Barbarian, before it) is, though. The totems aren't flavored as driving the rage or being a side effect of it. They're just abilities that get attached to the Barbarian because there'd otherwise be no reason to have the Berserker as a separate class, rather than a Fighter kit.
Really, there's probably a case to be made for creating a Warden (or similar) class that gathers together various "nature warrior" tropes. You could put Berserker here, but I still like it as a Fighter thing. Definitely put the totems as a Warden sub-class. De-emphasize the shape-shifting ability of Druids and give the Warden a shifter sub-class. Finally, remove beast master from Ranger and put it on the Warden.
That really just highlights the fact that all the nature/primal classes are a bit out of sync and need tweaked. Ranger is the best, after the latest UA update.