If you charge your laptop's battery to 100% all the time, eventually the battery life decreases and it will only ever be able to charge to like 90%.
So the solution is to have the laptop limit its charging to 90% to preserve the battery's life, but then any time you need to use the laptop away from your desk it only ever has 90% battery. How is this better?
We're told to do this with our EV but we usually know in advance if we're going on a long trip so we can change the limit and charge to 100% temporarily.