As previously discussed on Stack Overflow in Russian Meta, site analytics show a severe decline for quite some time. Here're stats of Ru.SO:
As you can see, all stats are on decline for two years. Answers and upvotes both dropped to about half of their previous values.
However, what we thought could be specific to Ru.SO, seems to happen on other localized sites as well, though to a less degree.
Pt.SO shows a similar trend:
The number of posts started to decline without even statying stable for a while. What's even more frightening is the crazy increase in downvotes at the cost of upvotes, something I've never on any other site within SE network.
Es.SO suffers from the decline the least:
However, even on the seemingly most stable of localized sites, the last half a year shows a considerable decline in posts compared to the previous year, plus answers dropped below questions long ago.
What's going on? Why is this happening?
Not so long ago, the localized sites were showing very strong stats, beating most of other sites in SE network. They were growing rapidly, accumulating a strong user base. But now all this is gone. They don't stabilize, resting on plateau of horizontal graphs, but show decline, some stronger than others.
Should we be concerned? What can we do to fix this?