About mental effort in meetings being lower than solving a technical issue, it is definitively true (most of the time), even though non-technical people cannot even grasp how much a difference there is.

In a previous software job, I was participating in a trade show. It was meeting after meeting, with both sales and technical aspects (I was paired with a sales guy). After several days like this, I remember vividly the sales guy saying how this trade show was good, but at the same time complaining how tired he was because all of these meetings. I kept it to myself, but for me, this was nearly like vacations compared to the day to day usual work