Yes, CK3 has a higher all-time peak on Steam than TF2 (and a higher player count at the moment of me writing this, as well). As for Siege, not so much. Siege's all time peak was over 163k players.
Yeah, we joke, but it kinda is like that. At the moment, it's more popular than any strategy game on Steam.
Out of curiosity, I went to compare CK3 and Civ 6 on Steam Charts and SteamSpy. Turns out that CK3 is doing really well: it has twice the number of players of Civ 6, twice the peak players, a similar median playtime, 10% higher user score, etc. However, SteamSpy estimates ownership of CK3 at 0.5-1 million versus 5-10 millions for Civ 6 - so it's not all roses. (They estimate CK2 at 2-5 million owners, BTW, and it's free to play...)
What I find the most telling from the stats is that the median playtime for CK3 is over 20 hours. This is comparable to Civ 6 and way ahead of CK2 (a meager 4 hours median playtime.) It's also very close to the average playtime which tells us that most people have played about 20 hours - not like in CK2 where the median was 4 hours despite the average being 60 hours (which meant that most people gave up right away while hardcore fans clocked hundreds of hours.)
What all this tells us is just how easy to get into CK3 is. Most people who pick it up continue playing. This is the biggest success of this game, and it really gives me hope for the genre.
