Apple and Android are.
But Android is far more diverse than just Google's distribution.
The companies who should be punished for anti-competitive behavior are the telecom companies. Not only do they restrict what devices can be activated on their networks, but they force Android users to wait months, years, or forever for them to dribble out a garbage-laden, proprietary version of the OS for every specific model of phone, one at a time.
And then there's the idiotic locking of phones; it's not just that it should be illegal, but it's also backward: U.S. phone companies lock the phones of people who are UNDER CONTRACT. Talk about stupid. These people are contractually obligated to keep paying, so who cares if they take their phones to another network? That's a net win for the phone company, since they're paying for NO service!
They both need to be stripped of their extraordinary powers so that user freedom and proper capitalistic competition can be restored.
It's likely that any regulatory action taken against Apple and Google will force the companies to innovate more and become healthier themselves.