Pc shut off while idle overnight and won’t turn back on

Hello, my pc was left on but idle last night, I only had chrome and discord running. The next day, I found my pc turned off. I thought it may have been a power outage during the night, but my clocks were all still accurate. I tried pressing the physical power button, but nothing happened. I tried the power supply switch as well, and unplugged the pc both from the power supply and the wall outlet before unplugging my lamp and plugging my pc into that outlet as well. No change, the pc remains off and unresponsive. It’s just over 8 years old, does this sound like the power supply getting old and failing? Is there a quicker and cheaper problem to fix that could be causing this?