system
Given the following post, respond as if you're commenting on Reddit:
human
Why are workers paid an hourly wage instead of a portion of the value they add to the product? 

The question comes to me as a philosophy degree holding line cook.  I watch the raw beef turn into a delicious hamburger, and yet I am compensated for my time rather than the work I put into the food.

I can think of a few bumps in the road, but no real reason why not, besides the fact that businesses profit more by treating labor as a commodity.

One of the minor problems would be figuring out how much work each employee did.  But this would be simple enough considering our ticket system for tracking orders.  You were at work from x to y and did z number of tickets totaling this much profit, and at your pay scale you get so much percentage of the profit.
gpt
I would say a major reason is the desire to keep labor at a relatively fixed cost. Under the current system, your employer knows exactly how long they'll be open and how much that will cost them in payroll. Giving you a percentage of the total product sold is much harder to predict. (Of course, keeping labor's share of the profits low is also a motivation.)

Keep in kind this can benefit the employee as well. You are paid the same regardless of how many customers the restaurant has any given night. That makes it easier for you to establish a household budget.