It's not free to build a platform, but I believe the cost has already been paid by the users when they buy their device.
No reason to have users pay twice, when they buy their device and when they try to use services on the device they already have.
No reason to have users pay twice, when they buy their device and when they try to use services on the device they already have.
The cost for the store platform is paid by the developers when they sell the app.