I track prices with isthereanydeal.com and yeah pretty often a new historical low is set by a Steam key reseller like Fanatical. It's usually only by a few bucks (like maybe $5 max, though still not a bad discount if the previous price was like $25).

Of course if I buy the game, I stop caring about its price so maybe the same sale happens directly on Steam sometime after. I'm not sure on that so ymmv.