I actually dislike ensuite bathrooms for myself. Like that there is separation for sleeping and showering/bathrooms. The moisture from the bathroom comes to the bedroom. On guest rooms it's can be nice that the guests don't have go around the house when they want to use the bahtroom.
Optimally, I'd say a house should have one toilet on each floor, and at least two toilets and bathrooms.
The huge benefit of the ensuite is not waking up the rest of the house if you have to get up in the middle of the night to use the restroom (which I often do). Also, don't get your comment about moisture from the bathroom. We have a fan and door on the bathroom which prevents any moisture from coming into the bedroom.
Optimally, I'd say a house should have one toilet on each floor, and at least two toilets and bathrooms.