In practice that doesn't really work. These companies rely on economies of scale, and make minuscule margins (and yes, investment capital, but that kind of goes away if you try to regulate profits into oblivion).
So reducing profits doesn't have much of an effect on consumers or drivers. Anything that profits one is probably going to cost the other.
To no small extent, this is something of the point in this case. These jobs straight up shouldn't exist because they're simply not profitable and many of them never will be; we're seeing companies with no hope of becoming properly profitable trying to push their costs onto their own employees, rather than simply vanishing as they should.
Investment capital is what they burn while they try to become profitable, and if that doesn't work, the company should vanish or find another investor willing to take the gamble.
So reducing profits doesn't have much of an effect on consumers or drivers. Anything that profits one is probably going to cost the other.