This looks roughly like first class on an expensive airline. Which IMO is a good sign: airlines came up with this configuration out of their overwhelming economic incentive to maximize comfort and privacy while minimizing space. So by definition this is likely to be the best solution.

In my (substantial) experience, sleeper trains tend to attract a certain kind of customer: hardy, extroverted types who aren’t too concerned about privacy, i.e. the kind of person who would stay at a hostel.

This new kind of accommodation, like the new Austrian NightJet and others, might at last broaden the market to other groups.