I’ll start with a few:

• Cyberpunk 2077 (PS5). Only 53.8% of players earned the “Lovers” trophy, awarded for clearing the prologue at the No-Tell Motel, and only 77.3% of players earned the “Fool” trophy for clearing the preceding lifepath part of the prologue. Which means that ~20% of the people that played the game never made it out of the character creator, and another ~20% of the people that played the game went out into the open world, faffed around for a while, and then decided they were sufficiently entertained & then went back to playing FIFA.
• Bonds of the Sky (PS4/Vita). You might have heard of Cyberpunk, but I doubt you’ve heard of this game, which is a low-budget Dragon Quest clone. It’s not one of those “pay us 3 dollars/euros/pounds games and we’ll give you an easy platinum” shovelware games that the PS4 had in abundance at one point in time, and yet, the platinum trophy has an insane 59% acquisition rate. (By contrast, Horizon Zero Dawn, a much more popular game with a trivial platinum trophy, has only a 5.4% acquisition rate for its platinum.) The few people that played this game must’ve really loved it.
• Bloodborne (PS4). Only 44.6% of players beat the first boss, Father Gascoigne, but 25.9% of players beat the boss that triggers the endgame to start. So FromSoftware lost half their players in the game’s first area (or the character creator again), but of the roughly half that made it out, roughly half of that half went on to finish the game. Talk about polarizing opinions.
• Kingdoms of Amalur Re-Reckoning (PS4). How common is it for players to rage-quit in the character creator in any given game, I wonder? Because only 69.1% of the people that played the game collected the “Reborn” trophy for clearing the prologue. I don’t get it; a 90% rate would make more sense, but even that would imply that 10% of their players started the game once, decided “oh hell no,” and then went back to playing FIFA.

What are others’ observations? All platforms with achievements/trophies are valid.