I don’t want to get in the way of your argument re. Usenet, but spinning hard drives will last longer if they stay on. Starting and stopping the spindle motor will impart the greatest wear. As long as you have the thermals managed, a spinning disk is a happy disk.
I’ve had a folding Samsung for the past year and it’s really great. The hardware and software do need time to mature (in fact, the phone is nearly useless in “folded” mode without third-party apps), but at this point I don’t think I could go back.