I don't think hackers have more of a chance of hacking your PC if it is on or not.. Most hackers these days are more concerned with crypto currency accounts, paypal, and other software accounts, Emails etc.. less so your personal files.
If a hacker has access to your PC or not, if it's on or not isn't a 'big deal' to the hacker. They will get what they want.
For environmental reasons and for the health and longevity of your PC i would recommend turning it off each night so it can start a fresh each day.