This is really a poor software solution to an old hardware solution that disappeared for the sake of thinness: removable batteries. In the past with easily removable battery packs you could simply pop them out once they're fully charged and pop them in when you wanted to make sure they were charged up. When manufacturers started touting long life cycle batteries to justify internalizing them and making them difficult to replace and impossible to quickly pop out, software manufacturers added this in to attempt or extend battery life.

Before, I simply removed my battery when plugged in all day and significantly extended my battery life. If I needed it, it was mostly charged. It would of course dissipate over time so if I had any plans of using my laptop in an actual mobile fashion or wanted to move my laptop from one long term power source to the next, I'd pop it in, make the move and pop it back out. I of course lost the UPS feature having a laptop with a battery pack also served but I could assess when I thought my power source was/wasn't stable and pop the battery in under those conditions (not very often).

Most people I know use laptops as portable workstations. If you frequently operate in situations where you desire battery alone then the OS charge management works quite well. I don't and most people I know don't. In today's world, mos the use cases I operate under those conditions are better served by my smartphone.