These "awesome" things I see in most modern games are things you either do by playing, or boring, repetitive things that don't really add any real replay value to a game unless you do already like doing that kind of repetitive things.
I mean, really, look at the steam achievements? Most RPGs will have achievements for "level XX," as if it was a wondrous thing to level up to there. Or hey, this one tank game I've been playing has achievements for killing up to 1000 tanks... Which is something you'll do if you do play X times anyways.
It's either that, or achievements for getting RNG-locked things, which are entirely independent from a gamer's skill.
Yes, there's achievements for doing things like killing certain bosses in certain ways, things that do require skill, but they're the rarest. And also, how would that really benefit Terraria, a game where most of the fanbase seems to have a mentality which can be summed up as "you can't do X unless you're (famous Youtuber.)"? You would end up with a lot of people complaining about "impossible" achievements.