> I wonder how this compares to GrapheneOS in practice.
https://eylenburg.github.io/android_comparison.htm is a fairly complete comparison. One of GrapheneOS' biggest features is that they sandbox Google services (if you choose to install them), whereas e/OS gives them privileged access by default (via microG). Calling it a "degoogled" OS while microG uses Google's proprietary blobs is... a choice.