Copied from a different comment of mine:
well, you see batteries should not sit at 100% at all and if so, only if you start discharging immediately. So just getting them discharged and charging them again to 100% where they will sit at for 20h a day won't help much against degrading the batteries.
"Choi 2002 shows that the constant voltage part is the most harmful to a battery, charging to 4.2V itself using constant current at 1C doesn't degrade it too badly, but by holding the battery at that voltage for an additional time causes most of the damage to the cell., [Source] (https://accubattery.zendesk.com/hc/en-us/articles/210224725-Charging-research-and-methodology)
I use a an App called Al Dente where I can set the maximum charge: https://github.com/davidwernhart/AlDente-Charge-Limiter
And there is also this: Basmati: https://github.com/aykevl/basmati
You can get it for windows too (googled that for you) https://www.thewindowsclub.com/battery-limiter-software-for-windows-10
For Linux my quick search found this: https://www.linuxuprising.com/2021/02/how-to-limit-battery-charging-set.html
I agree with YouTube but you can’t just spend days on end entertaining yourself. Your brain will adapt to your dopamine levels and everything will start to get boring (what you described with the game). You need to find things to do which are not dopamine pumps like a hobby or reading books.