Li-Ion batteries aren’t designed for that use-case.
Also the Magic Mouse has fast charging. You’ll get a full day of battery in 2min.
With a full charge, you’ll get 2+ months of usage.
Do the math. You’ll most likely charge this thing less than 20 times in it’s entire life.
That’s why the battery port design is both really smart and elegant. Unfortunately people don’t take the time to understand the purpose of design choices and jump to the easiest meme that reinforces their beliefs.