True, I'm definitely guilty of occasionally building solutions looking for problems - although this email automation piece was surprisingly not so.
I use it for two reasons, when training ML models, I setup the script to send me an email every 100 or so epochs, this sends a notification to my mobile where I can check the model training is running as expected, without me needing to be sat at the computer.
The second, almost the exact same process, but when I'm performing long-running ETL processes, to alert me when the task is complete.
I also had an old colleague who found it useful for automating his weekly reporting, and in another role I knew a who manager was using it to automatically send timesheet reminders to people who had missing time.
With what you said in time spent on email going over incoming mail, yes I fully agree, this would be useless for those tasks. But for tasks such as those above, I think it is a reasonable solution.