Where are you finding that number, 150,000? The instance in question has one one hundredth that figure and the Lemmy devs claim 27,000 accounts grand total.
Lemmy.world is 31k users alone. Beehaw.org is 12.k users (and each of those users at Beehaw.org were manually curated)
Maybe 150,000 is wrong, I saw it posted somewhere but I'm not sure what the methodology is. But between Lemmy.world and Beehaw.org we're already at 43k+ users.
