In resume: Epic want to be able to create their own online stores in devices that can reach people's hand so that people can have a choice from which store they want to buy from.
While Apple want to keep MONOPOLY of the stores on the devices they own.
Look, it doesn't take a genius to realize what is going on. Internet should be a free place and anyone carrying a device that can connect to internet should be able to buy what they want from WHERE they want in the internet.
I totally support Epic in this case.
I will always support free pathing, free market and free will.