I mostly leave mine on, but occasionally a cat will step on something that turns it off, or pulls a plug and they go off.
Most of my computers are expensive but last around 7 years or more.
I think I bought the one I have now around 4 years ago as a refurb for about the equivalence of 1000 USD, but my awesome husband bought and installed a ton of upgrades to it for my last birthday. He upgraded my RAM, put in a second hard drive ( so now I have a HDD for 1TB and a SSD for 1 TB) He fixed a latch and the battery connector and the thing runs better than ever.
I think it does not hurt when so many on this board either know/ or are relative experts on the PC !!!!
Somebody else less, might be looking a much shorter lifespan for their computers.