Quitting a job is already strictly defined by the contract.
Very strictly, depending on what country.
In my country you can not "just get up and quit" - there is a minimum of 30 days you have to remain employed to give your employer time to get a replacement for you.
In some work places this period is 60 days and often employers like to completely not pay you for those two months, even though they are legally obligated to.
In high sensitivity work places you can not quit until your replacement has been hired, trained (by you usually) and then accepted by your superiors as being acceptable.
These situations are usually either highly confidential or are simply crucial to a business so to even get a job like that you get to sign a very specific contract.
These are just some examples of employee restrictions that are obviously in favor of the employer, especially when you factor in a corrupt country where he can simply not pay you for those last month/two and yet you are literally forced to work (or if you refuse to cooperate then good luck ever finding a job in that country within your field of expertise).
What legal restrictions does the employer/tycoon get?
Lolz none of course.
Even if he had any legal restrictions or obligations he can just ignore them cause lolz corrupt judges and police.
And the corrupt politicians and military (that are payed by those very same tycoons who abuse employees) keep everything in that sh*thole state.