Currently there isn’t really any incentive to try to get the harder achievements since they give no reward and there is no way to show them off in-game. Most of the easy to get achievements have titles, which is fine, but when you get to the ones that are actually hard to get or take a lot of grinding and time, there isn’t an achievement for most of them.
As an example, there is the “Speedrunner” title, which you get from competing any level shard dungeon in less than 15 min, which is really easy. The achievement for doing a level 15 shard in less than 15 min has no title or other reward, but it’s way harder to do.
Or in the mini story pack there is an achievement to kill 30 of the giant dreadfang, but there is no reward for it, so why would you bother doing it?
There are many more of the achievements that you just don’t have any reason to do, because they don’t get you anything to show that you did them.