That's true, originally only users that posted or commented were counted as active. Then they changed it to count users who had voted as active, even if they didn't post or comment.

But I believe that change occured almost one year ago, in March 2024. You can see a big spike of active users at that time. Starting this January we've seen some really nice organic growth, although it's not nearly to the level of the API exodus. We still need more users, but it's really encouraging to see some solid growth after over a year of stagnation/slow decline.

Yes, back then you had to comment or post. These days it also counts users who vote within the timeframe as active users.