Unaugmented mundane humans are, to be sure, a suboptimal choice. The design of the game dictates that. Magic and augmentations give higher dice pools (by increasing Attributes, increasing skills, and giving dice pool bonuses) and higher initiative scores (letting PC's not only go first, but go more often). This fits the theme of the game, too. Normal people are supposed to envy and fear the awakened, and be tempted by the easy boosts of augmentations. It would break the transhumanist feel of the game if an average Joe could match the feats of an adept or a street samurai.
That all said, though, SR5 lets you create some pretty effective unaugmented mundane humans. Using Priority, you can take A: Attributes (24 points), B: Skills (36 individual skill points and 5 skill group points), C: Metatype (for an Edge of 7), D: Resources (50,000 Nuyen, an ample amount for someone with no foci or augmentations), and E: Magic or Resonance (mundane, obviously). Sum-to-Ten is even better, because you can drop Resources to E (spending 10 Karma for extra starting money gives you 26,000 Nuyen, still enough for starting runner essential gear) and raise Skills to A (46 individual skill points and 10 skill group points!).
So what do you all think? Are unaugmented mundane humans more playable now? One note: I really didn't include deckers in this discussion, because their abilities depend more on gear than on magic or augmentations.