I'm on /e/OS and don't use Murena Workspace (which I think is just a Nextcloud instance that they host). For the past couple of years in which I've used it, I have felt zero pressure to use Murena Workspace. Though I imagine it might be neat if you host your own Nextcloud instance, which might be nicely integrated too.

(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.)