I just noticed that we have now officially passed 100,000 posts on the main site, by post ID.
Thanks to all of you for contributing, and keeping contributing!
Apparently we haven't, quite yet. The count in SEDE is correct (as of its last refresh). I asked about the discrepancy on Meta.SE and learned that not all ID numbers are actually used.
We're close to 100k but not quite there yet. I'm confident we'll remedy that before too long.