No. Play Services is Google's way to make Android closed source. Many new features don't get implemented in Android, but Play Services. Many apps don't work (correctly) without Play Services.
Being closed source is not the goal. Update speed, consistency across the ecosystem, and feature development speed are key reasons things are implemented via play services. Also dependency on google services, but that's not relevant here. AOSP is greatly improving in its ability to tackle these things, so the choice to implement things in play services won't be as compelling as it is today for things not ultimately tied to Google.
Play services is how Google delivers many Android updates now so that all users can get security updates without waiting for the device vendor to publish it for each device.