RSUs are taxed as income according to their value on the day they vest. Companies can offer employees below-market grants, but the difference is recognized as a cost and (eventually) has to be approved by shareholders.

Stock options with a strike price below market also have tax implications for both the company and the employee.

Equity based compensation essentially comes out of the hides of shareholders: As long as they are happy (and people aren’t playing Thiel-type games), it’s not as terrible as you make it out to be. There’s a limit to what buybacks can do to juice prices and equity generally puts people into a long term mindset.