Leave it on?

Both arguments seem valid. I myself have a 25-year-old Harman Kardon integrated amp that has been turned on and off for almost every use and is still fully functional. However, remember that heat is still the worst enemy of electronics, so I would suggest leaving it on or in standby mode during the day when you’re actively listening. But if you go on vacation or will be away for an extended period, I don’t see any good reason to leave it on. Occasional power cycling won’t harm the gear, as it’s well within the design tolerances.  My Parasound a23 PA is running 126 deg F inside the chassis and the Harmony micro DAC is running 104 deg F on the top of chassis (so could be even higher inside).  I really don’t think it’s a good idea or good practice to leave it on all the time—unless you can convince someone that the high temperature won’t cause any damage to or degrade the performance of the electrolytic capacitors inside.

I have checked up on my equipment.

Grimm says to leave the MU1/2 on and currant draw is scant.  

Weiss DAC501 consumes 2.2 VA in standby. Some think a twenty hour warm up is key. In use DAC uses 25 VA. 

AudioQuest Niagara Says leave on or off.  I keep on as streamer is connected as are low voltage PSU’s for swich and filters.   

Tubes on for use only  

The internet AI reports it Depends on priority. Best sound = keep it on (except Holliday’s or if you listen very rarely of course), Best for your wallet = switch it off. Always turn your equipment off if you are not going to be using it for a few hours (that’s not great advice) and always turn it off of you are leaving the house or over night.

Yes , for me, if away it all gets turned off  Not good if you need yr. roon core and are using remote?????

I suspect/know darn well that other things in my house suck way more juice than standby audio gear. Internet is connected to so many things and they all are on and drawing power. Kill your television. 

Given switches location on Subs turning off very unpractical. 

Plinius said leave my Class AB integrated on all the time. Their newer ones have the power switch on the back panel. My phono stage doesn't even have a power switch (Sutherland Insight LPS) - if it's plugged in, it's on(unless your power conditioner if unplugged or off).

I know it's socially acceptable to not really care about the planet anymore, but you should turn it off.

We all know that coal is now the cleanest Energy producer that's available, but still good idea to turn off your equipment.  Most ss equipment is durable enough to last a lifetime.