Generally speaking it’s better to keep it plugged in than to repeatedly charge and discharge it. But it’s even better to keep in plugged in at 80% charge instead of 100%.
Really? I'm not very knowledgeable about the subject but I always understood that discharging the battery was healthy. Is there somewhere I can read up on why that is?
It is healthy, but discharging to 0% isn't and keeping it at 100% isn't either.
It is best to plug in at 20% but only charge to 80%. Then every half a year you do a full charge to 100% and a full discharge to calibrate the battery management.