>Operated by Murena, your Murena Workspace account @murena.io is at the centre of the ecosystem, allowing to store, back up and retrieve your data safely on remote servers.
This sounds like their version is somewhat married to Murena. While probably better than Google, still not independent.
They're also advertising features such as "hiding your IP address [...] when you feel like it" – which sounds a lot like a VPN – without mentioning much about who the traffic is going through or how they might log it.
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.
The GrapheneOS developers are very sceptical of e/OS (https://xcancel.com/GrapheneOS/search?f=tweets&q=e/os), but you should obviously take biases into account here. Murena's CEO occasionally participates too: https://xcancel.com/gael_duval/search?f=tweets&q=grapheneos
(That said, yes, I don't quite trust their VPN or app store, since it's unclear who's running it - in the latter's case, I imagine that's also a legal matter.)
This is usually not a good sign.
I'd prefer to have an OS provider that does one thing well.
You can do this on any other android device using an app like Orbot or Tor VPN beta