Interesting question. Mainly as mentioned above we needed Google Play Services for AR. Nothing else stands out at a high level.
However there is a clear bottleneck with the Google AR team for features that the community really wants. While it's understandable, perhaps the open source libraries aren't the priority or there's short staffing, there are issues like this one - https://github.com/google-ar/arcore-android-sdk/issues/153 - that have been open since Jan 2018. This one asks that we can use the smartphone flashlight simultaneously with ARCore, but there's no visibility on how close we are at the moment. This feature would have likely improved our work's performance greatly, but even in general, many other AR developers are asking for it.
Re: overcoming it, there's not much we can do in this case. We just didn't implement the feature.
I apologize Sriram I actually I meant to ask that to the user jmnicolas who asked you to for de-googled application; Yet you provided valuable information.
Long standing issues/feature requests are typical of Google's Android ecosystem, Regardless I eagerly await for your release. I think ToF based spy-camera detection could make a great addition to the women safety apps in India.
What were your biggest reliance on Google services you found in this 1 year and how did you overcome it?