This is one of those interesting "mesofacts" that is related to how batteries used to work. It's similar to when well meaning people share anecdotes about car maintenance that were only true back when cars had carburetors. These are hard lessons learned that are not necessarily applicable today.
It's certainly true that the old nickel cadmium batteries were harmed by continuous charging. But nowadays with lithium ion batteries, lots of laptops, batteries, and chargers all have little microcontrollers on them that can be smart about charging and maximizing the lifetime of the battery. The short answer is that you should read the manual that came with your particular system and see what it advises.
It's certainly true that the old nickel cadmium batteries were harmed by continuous charging. But nowadays with lithium ion batteries, lots of laptops, batteries, and chargers all have little microcontrollers on them that can be smart about charging and maximizing the lifetime of the battery. The short answer is that you should read the manual that came with your particular system and see what it advises.