Rootkovska has been (imvho rightfully) criticized in the past for selling isolation but dismissing the attack surface in Xen. I think Genode can help here:

https://twitter.com/rootkovska/status/949297922998489088

Though I believe thegrugq / ioerror have a point when they say that hardware compartmentalization is superior than layers of SW virtualization:

https://twitter.com/thegrugq/status/515085244198703105

The threat model is relevant though: In that aspect QubesOS has some problem finding an audience. I personally like it (I'm an active user) ... but mostly because I have a fetish for privacy+security and I like to play with new stuff. However if you push a journalist or activist or anyone facing real risk to learn QubesOS (the learning curve is huge for the general user), it makes more sense to just invest in HW based compartmentalization instead. HW compartmentalization can easier be trained and there is less likely a chance of shooting yourself in the foot. It's not a tech that anybody whose life is under threat should be using. First rule here not to use tech in the first place, and for cases where the risk is marginal use HW based isolation ... then there is nothing for a long time followed by things like QubesOS, Signal etc. These things are just good enough to hide an affair but it's reckless selling them as serious solution to tech-illiterate folk who have something to loose.