If you apply for a patent for invention or utility model, you can compare the advantages and disadvantages of the two methods:
Compared with the Paris Convention, the PCT procedure has an "international stage" procedure, which has the advantage that the applicant can go through the formalities of entering various countries within 30 months after the first application, while the Paris Convention only stipulates the preparation time of 12 months, so compared with the Paris Convention, the preparation time for PCT entering foreign countries is more sufficient;
Cost: Compared with the Paris Convention, PCT needs to pay more for the international phase because it has more international phase procedures.
So if you need more time to prepare and consider whether to apply for a patent abroad, you can choose the PCT route; If you have decided to apply and the materials are ready, you can choose the Paris Convention, which can save the cost of the international stage.