H1B is terrible for the employees, and for those who work alongside them. Companies try to slow down green cards, and use H1Bs as virtual indentured servants. They also fake looking for Americans- in practice, many of the jobs are earmarked for a specific person, and you are wasting your time applying for it. Losing your job as an h1b requires you to leave almost immediately, which isn't great for anyone. Hopefully t…
The "without chaining it to a specific company" is critical. When the employee is chained to a company, the company has every incentive to lie then treat the employee poorly. When the employee is not chained to the company, the company has incentives to tell the truth then treat the employee well.
The only ones who are interested in a visa like this would be foreign-born skilled workers looking to immigrate, and they are going to lose the fight over who gets the visas with people who have no specific skills but family in country since that family can vote.
There is no constituency for such a visa, so it is never going to happen.