Wow that's hard to figure out, I went looking for games I had the most achievement completion and tried to find which one had achievements most people had that I didn't:

• I never scored 6 goals in one game in Rocket League (60.5% of players did)
• I never stabilized Gale's Orb in Baldur's Gate 3 (44.8% of players did)
• I never became the champion of Fort Joy Arena in Divinity Original Sin 2 (42.2% of players did)
• I never saved the Printer in Dishonored 2 (31.2% of players did)