That you have no problem with odors is due to your personal sensitivity. A recirculating fan can never eliminate all odors. It bothers me.
We have Miele recirculating system with activated carbon filter. The odors are not satisfactorily removed there. Maybe it is also because Miele sells bad stuff and there are better manufacturers. However, it is more likely that such an activated carbon filter only manages part of the odors. Frying produces a lot of smoke, and where should it go with recirculating air? Several kitchen builders have also confirmed to me that they personally only want exhaust air for this reason.