I have some bad news for you. “Elite-class, university-brainwashed, liberal arts people” write about stuff through their biased lenses everywhere, including Nextdoor.
How many historical nextdoors are you aware of? For me, none. But is that because they don’t exist or just that no record survived? Social media is secret society.
You clearly aren't getting my point.
I'm arguing for 100 biased-perspectives over 1 biased-perspective
They probably aren't even reporting the final numbers in the local council election.
Assuming NextDoor's dataset is around in 100 years (probably not) there will be some topics well represented. But you are going to have huge gaps in others.