The Google Play Store and Google Apps are not components that make Android work. Android can function without them. The basic function of an operating system is to run programs. They have more advanced functions than this and can be enhanced with additional tools from the creator of the operating system. First-party tools in the form of app stores and other programs made by the creator of the operating system can enhance the experience but are not required.
Google is facing anti-trust scrutiny. In a general sense, I do not think that Google violates the spirit of anti-trust. That is my opinion. The reason for my opinion is that Google gives Android away for free. Others are free to apply Android as they deem fit. Google does have the right to not associate their brand with anyone’s release of Android under U.S. Trademark.
They are also free to associate conditions with the use of that trademark. Others have made their own version of Android with nothing visibly Google related on those versions. The core problem for others seems to be around permission to have the Google Play Store on their devices. They feel that lack of access to the Play Store and Google apps diminishes the desirability of their solution.