Looks like PurpleMonkey and Miniman both took the time to write good, thoughtful answers to this question: Do dragons of all sizes get lair actions and regional effects?
And it looks like they were posted within 3 minutes of each other - so probably both were written independently, and one wasn't copying the other. But they're using basically identical reasoning, with many of the same quotes even, and coming to the same conclusion. So, strictly speaking, I don't think Posterity(tm) is improved by having both around.
But, I also don't want to downvote or flag either answer - on their own, they're good answers!
What should we do in this situation?