You can tell this meme was made by a Gen Z/Alpha gamer because games generally didn't used to measure 'completeness' since that's primarily measured today by trophies/achievements.
Sure, some games might have shown a percentage on your save file and of course you could find/complete everything in a strategy guide, but even those might not have shown absolutely everything including but not limited to Easter Eggs.
Edit: I grew up with a Sega Genesis, Gameboy, and eventually PlayStations.