I think this is BS. The developer is not required to release their apps on the Apple platform. The consumers can elect not to buy Apple's product.

Now this case can proceed, then what stops consumers or sellers from suing Amazon, eBay or Google Express? They are a monopoly in their own domain.

Amazon, for example, charges 15% for sellers fulfilled for every sale. The fee is even higher if the seller elects to be filled by Amazon.