It's not nothing. Maybe not worth 30% but it is worth something. They run the store, buy the servers and pay for the bandwidth. Pay the engineers to develop and manage the infrastructure. Run the app certification process. Maintain the security of the platform. etc.
If they can't charge their 30% cut, they will need a different business plan. Possibly charging app developers directly for access to the app store. They are not going to just give up their 30% and do nothing.
It's not nothing. Maybe not worth 30% but it is worth something. They run the store, buy the servers and pay for the bandwidth. Pay the engineers to develop and manage the infrastructure. Run the app certification process. Maintain the security of the platform. etc.
If they can't charge their 30% cut, they will need a different business plan. Possibly charging app developers directly for access to the app store. They are not going to just give up their 30% and do nothing.