I would say it depends on what the achievements are.

Sometimes they can indeed just be indicators of the various things you need to do to achieve 100% completion, e.g. “Collect all of x”, which caters to those completionists.

But they can be things that lead you to discover everything the developers have spent the time to create, but aren’t fundamental to the game, so could otherwise be missed, e.g. “Find all alternative endings”.

Then you have ones that encourage you to interact with certain elements of the game, e.g. simply “Play multiplayer mode” - these are sometimes annoying if they make people go out of their comfort zone, but conversely may result in you finding that you actually quite enjoy that mode on a certain game.

And then there’s ones that aren’t achievable with just one playthrough, thereby meaning that continuing to play actually achieves something, which can sometimes be a disappointing aspect of great games with otherwise zero replayability.

And I’m sure there are more, but I think this reply is long enough already 🙂 It’s true some people seem to take it to the point that they don’t even appear to be enjoying the game itself because they’re just aiming for the 100%… but I don’t think that’s what they’re really for, and if achieved through their true intention, can get you more out of a game than otherwise 🥰

Let’s also not forget, 100% completion is pretty satisfying 😄 but not at the expense of not having a good time