Hiruzen led the village for around 45 years if not longer. The Sannin became his students when he was 24, so he fought in all 3 Shinobi Wars, retired, lost his wife and then had to take the mantle of Hokage again when he clearly wasn't interested any longer
Konoha exists because of Hiruzen and the fandom is too obsessed with him not personally being a dad to orphan Naruto to see that he's a wildly successful leader