Speaking for scalable (variable) income and against fixed salary is easy.
Everyone receiving a fixed salary, or hourly wage, or $X per month, would tell you how they have not been compensated in fair due.
And then there is this annual pay increment exercise that comes once every 4-seasons.
I never understood why it only happens once a year.
The other issue is a sense of equity.
You inject 100% of your time, effort, and energy throughout the year and only receive a 3%, 4%, or 7% pay increment in return.