It is exactly the same as why we can't drive as well while on the phone.
When face to face with someone every possible audio frequencies emited by the other person will reach you. This means your brain won't have much work to do to make sense of this information since it is 'complete'.
In a zoom meeting in most cases everybody is on his laptop using the built in laptop microphone. This means the sound will be mediocre at best concidering there isn't any network issue. Voice quality will be compressed and lack certain frequencies that you don't notice but help you decypher more quickly the other person speech.
That means that the brain energy necessary to only be able to understand the person in a zoom meeting for the same amount of time is more important than in a real life meeting.
My squeezebox radio is a damn fine machine with the best sound among my bluetooth speakers, but it is now almost completely useless since it has not been updated in years and spotify dropped support.
This is planned obsolescence at its worst, opening up firmware once you drop support for a product should be mandatory.
When face to face with someone every possible audio frequencies emited by the other person will reach you. This means your brain won't have much work to do to make sense of this information since it is 'complete'.
In a zoom meeting in most cases everybody is on his laptop using the built in laptop microphone. This means the sound will be mediocre at best concidering there isn't any network issue. Voice quality will be compressed and lack certain frequencies that you don't notice but help you decypher more quickly the other person speech.
That means that the brain energy necessary to only be able to understand the person in a zoom meeting for the same amount of time is more important than in a real life meeting.