Gamification is a new form of employee abuse that people haven't yet recognized as abuse. It's only a matter of time before we all acknowledge it and ban its use in a work setting.
humans are competitive (and also cooperative). we like to know how we are doing, and gamification facilitates that while also relieving boredom from an otherwise tedious task (something i do often just for myself).
That was already known via driver ratings. No one considered that "gamification" because it's a basic KPI.
The "lab rat" aspect of this comes into play with some computer-generated BS "challenge" like "“Complete 34 rides between the hours of 5am on Monday and 5am on Sunday to receive a $63 bonus.”
In videogames, this is called "grinding", aka gaining experience points doing tedious, repetitive tasks, in order to proceed to the next experience level. The difference is, video game players aren't doing something that requires the same level of attention and duty of care as a car driver.
but i view your example (a $63 bonus for 34 rides) to be more an incentive than a gamification because it involves real money, not simply "meaningless" points.
ratings are more akin to gamification in my view because (1) they're not directly tied to an incentive, and (2) it takes advantage of our human nature of wanting to do well, especially when it involves how other people view us.
what i would suggest is better is to bridge the information asymmetry between contractor and contractee in ways that meaningfully allow people to make considered decisions about work. so instead of trying to protect the worker from a dopamine hit (you can't), demonstrate to them how gamification really works (from both sides). in addition, let's create a real liquid labor market so that the worker can legitimately evaluate and choose a different job if this one sucks.
then, if they choose to drive for uber/lyft, it's a considered and affirmative decision made on a level playing field. yes, this is really hard, but we can do it.
Maybe for children who don't know of future opportunities and what job expectations are, but anyone with a past job can easily compare.
Also, those 'rewards' that make noises and tell you 'GREAT JOB', get old. Seeing 10 unread notifications on facebook does not get me to click like it used to.
The concern is that a simple 'ban it', is a dangerously simple approach.