Yes everything has value because people agree so. The same applies to fiat. In reality, fiat is just a piece of paper and we all agree that it has value. The only difference between fiat and Bitcoin as well. People can use tokens to transfer values globally, because tokens have a perceived value that is determined by supply and demand on the open market.
Bitcoin has value because it is as valuable as money. Bitcoin has properties of money based on mathematical formulas rather than based on physical form or belief on the center. The value of bitcoin comes only from people who are willing to accept it as a means of payment.