I don't believe the OP was talking about on/off cycling during a particular listening session. But resting the equipment between listening sessions. People are different and have different schedules.
I am not retired and work during the day. When I get home and feel the need to sit and listen and enjoy music, I turn my system on about an hour or so before listening and when done (because I have to go to bed and sleep to get ready for work the next day), I turn the system off. I think this is mostly true for most people.
Retirees on the other hand, may listen for a few hours, leave to run some errands or some such and come back home and want to start listening again.
No big deal. I would still turn my equipment off anyway. Modern equipment should not have any on/off cycling and current inrush issues because they have inrush limiters or slow start circuits that limit inrush. Also, some electronics don't have circuits that drain capacitors when off, so many times the capacitors still have a charge on them anyway after a few hours, so again, there is limited inrush current.
The only cycling issue would be the switch itself and maybe the bridge diodes. But, I wouldn't count on that either.
If you are going to leave for a few hours, I would turn the equipment off. If it is solid state, (with exception of class A amps), there shouldn't be a problem leaving them on. Like I said, personally, I would turn it off anyway when I leave. I don't like having electronics on when I'm not home. Refrigerator notwithstanding.
But, leaving tubed equipment on that don't have standby circuitry is simply asking to replace the tubes much earlier than necessary.
enjoy
