Because visa and mastercard are credit card organizations all over the world, which are more suitable for the whole country, and UnionPay is a bank card issuer in China, which is a state-owned institution. It issues not only credit cards, but also debit cards. Most of its products are covered in China, so it is not feasible to use them in France. Moreover, from the perspective of distribution area, both visa and mastercard belong to American card organizations.