Everyone in tech whose job is a bet on the future success of a product should expect to leave it. Expecting 100% of products to have 100% success in 100% of economic environments is a bit naïve.

Just to point out Facebook is a success and is still making insane profits every single day.

They aren't losing money or posting losses.

The employees don't have control of the company, and they agreed to not have control when they signed on. If they want to control, they are free to start their own company, invest capital to get more voting rights or provide enough value that the company wants their input enough to give them voting rights. Also, just getting another job is an option... But I admire what seems to be a very generous severance package, which is not legally required on the part of Meta.