Is it okay to buy an international ticket and give up connecting flights to leave early?

Yes. If the connecting flight is abandoned midway, all subsequent itineraries will not be able to travel according to the original plan. According to the relevant agreement, once a passenger terminates any one leg of such a connecting (connecting) flight, it means that the entire trip is voluntarily cancelled. In other words, the return ticket that the passenger did not use will also be invalid and cannot be used.