If all rights were inalienable, an employment contract would not mean I need to pay my employee, because I would have an inalienable right to keep my own property (cash).

Also nobody would offer the contract in the first place because the employee would keep their inalienable right to choose how they spend their own time (not working).

EVERY contract is about giving something up in exchange for getting something. In most legal systems a contract is void if either party gives nothing. So in a world where nothing can be signed away, no contracts exist at all.