Do not look at the Processes tab in the Task Manager or the graphs in the Task Manager. They are not accurate. Always use the information in the Details tab instead.
When testing your C0%, exit Google Chrome. When I exit Chrome, it is completely gone from the Task Manager. I think the default setting is for Chrome to run in the background 24/7. I do not see the point of this. Perhaps you have some plug-in that is constantly updating. Google Chrome has an option to turn itself off if you do not need it running all of the time. Many programs have options like this, hiding somewhere within their settings.
I have never disassembled my laptop.
This is basic maintenance for a laptop. Most laptop owners do zero maintenance. Their laptops run hotter and hotter and slower as they install more and more useless junk until they finally get fed up and sell it or dispose of it and start again with a new laptop. It does not have to be like this.
Many laptops are simple to open up and repair. Search YouTube for your specific laptop model. Watch more than one video. I do. A heatsink that is full of dust and dirt will block air from flowing through it so it will be unable to cool the CPU. A vacuum or some compressed air can make a world of difference. When you get more confident, you can pull off the heatsink and replace the thermal paste. I am sure there are lots of competent techs out there but I care more about my computers than anyone else does. Learn to do this maintenance procedure yourself. No one ever does a perfect job the first time they replace the thermal paste so do not live in fear about doing a bad job. You only learn by doing.
Check out the C0% when my computer is idle. There is no useless crap running in the background.
Now compare that to your computer. There is lots of room for improvement.