Exhaust fans must be ducted so that there is a place for the exhaust to go.. space and introducing it into smaller spaces with little to no access for maintenance.
The kitchen I'm ok with out a hood fan, but I'm not liking the idea of the bathroom not having an active ventilation fan. Especially after a shower .
I moved in an apartment 4 months ago. At the first day I move in, I realized that the vent fan in the bathroom is not working. I told the management office the next .
When inserting a new internal wall care should be taken not to make any other. with a mechanical extract fan to reduce condensation and remove smells.
Every house I have lived in has had the fans venting into the roof space.. If it is in a bathroom without a toilet (or with a toilet and an openable window greater than 5% of the floor. I'm pretty sure it is illegal in some states.