Yes, it is voluntary. Your employer has likely made consequential financial plans on the assumption of your continued employment. He might have entered into c

Yes, it is voluntary. Your employer has likely made consequential financial plans on the assumption of your continued employment. He might have entered into contracts, invested in equipment, etc. and yet you can quit and trash those and happily be at work the following day for someone else. At will employment is truly a voluntary exchange. (That is why many people have contracts.) Again, however I agree some level of worker protections are reasonable for a pragmatic reasons at a societal level, but not because of a power asymmetry at the employer employee level.