Antitrust law is there to protect consumers, not your business model.
As a consumer, I don't want to have to use 23 different wallet apps on my phone but am happy to have one secure implementation that's easy to use. You could argue that Apple Pay imposes lots of processing fees that will raise prices for consumers as vendors pass on processing fees to consumers and that prices would be lower if there was more competition, but I highly doubt this is the case in reality as Apple Pay processing fees are the same as regular payment processor fees for merchants.
As a consumer, I don't want to have to use 23 different wallet apps on my phone but am happy to have one secure implementation that's easy to use. You could argue that Apple Pay imposes lots of processing fees that will raise prices for consumers as vendors pass on processing fees to consumers and that prices would be lower if there was more competition, but I highly doubt this is the case in reality as Apple Pay processing fees are the same as regular payment processor fees for merchants.