MOLD! Homes that have poor venting that just vent into the attic
eventually grow MOLD. MOLD is unhealthy! People don't buy moldy
houses!

I've had my best friend walk away from 3 houses because the inspections
found mold in the attic due to poor ventilation. 1 house was bulldozed
after inspections found it was uninhabitable.

ALWAYS vent to the outside air. It may cost a bit, but well worth it
if your house is your nest egg. Nothing worse than seeing your nest
egg bulldozed because of toxic mold.