you must be printing them in ABS for them to wear that fast, try PLA - it's significantly harder and should last a very long time.
If you want larger teeth, then put fewer teeth on each gear!
As for tooth profiles, I've used others' work for those, and I'm sure they're simplified. These gears take long enough to render and slice as it is! If you want to post an updated involute gears script with better tooth profiles, or for
greatest win parametric resolution on the tooth, that would be great!