You can still run Android without Google Play Services, even though it's not a great experience.
Granted, there are tradeoffs. iOS is more secure in this space than Android, but Android is far more open on what you can do.
For example, Amazon created an app called Amazon Underground that would let you purchase and sideload apps onto your Android device from Amazon. Some of these apps didn't exist in the Play Store, so you had a viable option to buy exclusive titles from someone else.
On iOS, there is zero opportunity for a situation like this to occur. Everything must go through the App Store, and that's why I view it as a monopoly.