when the computer has nothing open
When a computer is idle at the desktop, it needs to spend hardly any time in the C0 state processing the background tasks.
The cores will spend most of their time in the C7 state where they are not creating any heat. The cores are spending over 99% of their time in the low power C7 state when my computer is idle.
That is problem #1. You have a LOT of stuff running in the background that you are not aware of. You have added software to your computer and are not aware of how big of a load it is putting on your CPU.
The next problem is that your cooling system is not adequate. Have you ever cleaned inside your laptop and replaced the thermal paste? This is called normal maintenance. Most people do not bother, wonder why their laptop no longer runs as well as it used to, buy a new laptop and the cycle repeats.
A single core load has your CPU constantly thermal throttling.
I call this denial. The log file shows constant temperatures in the 95°C to 100°C range. Either fix the cooling or learn to live with a laptop that is overheating and performing poorly.
Use the Task manager or the Resource Monitor to get a better handle on what is running on your computer. You installed it so it is your job to delete stuff that is useless.