IIRC predictive text input is also licensed from someone.

RHEL (Red Hat Enterprise Linux) is actually also 100% open source (which is one of the reasons CentOS exists). What you are actually paying with the subscription is:

• access to support (both the "stuff doesn't work" and "it would be really nice if you could add feature X" kind)
• access to updates & security fixes
• API stability guarantees
• software certifications
• long term (10+) support for major version releases
• making sure the company that makes your OS can both maintain and improve it

I wonder if something like this could improve the current information in the field of mobile devices and their operating systems. The current situation basically motivates device manufacturers and OS vendors to make people buy a new device regularly, as they only ever get money from people when they buy a new device (discounting some provisions from adds and paid app sales in app stores). So they don't release updates after a while - including critical security updates, release updates that make perform badly on older devices, etc.

With a subscription model both hardware manufacturers and OS vendors would have an incentive to not drop support as long as enough people with a given piece of hardware are subscribed.

Still the question is if enough people would be willing to accept paying for an ongoing OS subscription given that they are used to the current model where you get the OS for "free".