if it's impossible to dilute the worker, it's impossible to fund the business.
Lets say your startup sells 20% to an investor (round A), keeps 50% for founders/direct employees, and allocates the remaining 30% to "workers", i.e. drivers, employees. Now you run low on money and go out for round B.
Where is the equity for the round B investors? Say they want 50%, who takes the dilution? Just the round A investors and founders, taking them down to 6% and 14% respectively so workers can stay at 30%? Thats never going to happen, the B round investors aren't going to give funding to see founder incentives massively reduced (unless they plan to replace founders). They want the people they think are most likely to make their investment successful to have the most skin in the game, and that's very unlikely to be workers/drivers.
Also when an investor gives a management team and workers a big round of financing, they typically expect preference in future rounds. Especially if you don't achieve your promised objectives, your A round investor doesn't want to take the same amount of punishment as you will.
Whether you are an employee or a driver, you will almost always get common stock. Investors will get preferred stock. Preferred stock can have all sorts of negotiated rights, but almost always it means that they will get their investment back before common shareholders get a dime. This kind of structure actually makes venture capital possible, the vast majority of investments fail and being able to recover some of their investment from many of them instead of a huge smoking crater keeps funds going until they finally book a big winner. So if your company takes $200M in funding and then sells for $200M, the only payout employees can hope for are retention bonuses for key players.
What Juno did looks really sleazy, given they supposedly only raise $30M and sold for $200M liquidation preferences should have nothing to do with it. And drivers got restricted stock grants, not options for common shares. The difference is options are worthless until the option price is reached. RSUs are typically structured so you always get value, you don't have to reach any exercise price. No idea how they could only end up with 2 cents per share unless Juno had 20 billion shares, which is ridiculous.