Until today, I never new there was debate on this topic...

In another location, a poster strongly suggested that the prevailing wisdom of using a ground cloth below the tent floor was incorrect. This was their argument:
if your “barrier” is between the ground and your tent and there’s water in your tent you’re screwed. If there’s water on your tent floor and there’s a barrier between you and the floor, you’re obviously less likely to get wet.

Someone else posted this link:

I'm not sold (at all) on this theory, but I'd be very curious to hear others perspectives on the topic.

To be totally transparent, I don't regularly use a ground cloth. When I do, it's purely to protect the bottom of the tent floor so it lasts longer, and I've always put it between the tent and the ground.