Benevolent article on /e/ from the German security blog mobilsicher.de
The verdict here in a quick English translation (DeepL with some own minor corrections):
„Through the correspondence with the spokesmen of /e/ it becomes clear to me once again what I already suspected: The detachment of the operating system from Google is a lot of work.
The beta version is already largely Google-free, but not yet complete. According to the foundation, apps that normally use Google Play services for their operation run on /e/ with microG, an open source, tracker-free variant of Google Play services. In some cases, Google servers are still needed, for example for the push messages of some apps - but according to /e/, the data transmitted are being made anonymous.
The system updates for /e/ come automatically over the Internet, just like with Google’s Android. For detailed information about upgrades of the different devices (e.g. from Android 9 to Android 10) it is too early for now - first of all the first final version of /e/ is supposed to be released.
Although experts express critical opinions on the current state of the OS, personally I think: The developers of /e/ have come quite far in their efforts to create a Google-free, data-saving Android for everyone. The only downer is the self-built App-Store - here the e Foundation should definitely find a secure
solution. In use, /e/ is already convincing.“
When the author speaks in the last paragraph about experts and critical opinions it is not unlikely that he refers for instance to opinions such as the one expressed here: