I guess there are two issues here.

1. If a driver or any other employee is contracted to a team the team is obligated to meet their responsibilities and ensure wages are paid. It is the same in any business.

2. Drivers are paid way way way too much - this is the same in many sports and is the reason many professional teams are struggling to survive, it is up to the teams as a whole to set the wage structure in such a way to allow them to continue in the sport. i.e. if all top teams offer a similar wage to drivers all teams could survive, it becomes a problem when one or two mega-rich teams offer stupid amounts for a driver. It is not all about greed from the drivers point of view, it is about ego. By this I mean that if driver 1 considers himself to be superior to driver two, he will demand more money than driver two is being paid. Then along comes driver 3 who thinks he is better than driver one, so he wants more money than driver 1, but then driver two is better than driver 2 so he wants more, so driver one wants more and so on......