So, to clarify because there seems to be some confusion, this thread is about the unfocused nature of the mission system in game. It's about the fact that missions on offer seem arbitrary and unfocused, with faction offering the mission and location being apparently completely random
The unfocused nature does several things:
1) Replayability. Its a simple "go here and pickup data, or survey". There is no deep lore or hidden meaning behind these "fetch quests" so they can be issued several times throughout the game. This is good for both something to do (cash wise) and if you hit rock bottom and get wiped by a surprise pirate / enemy faction raid and need a way to get back into the game reliably.
2) Unlock future content. You can get high level stuff like blueprints, synchrotrons, and nanoforges, all of them good for cash now so you can buy cool ships, or keep them for the mid-late game colonies.
3) Same as above, allows you to find a good place for a colony should you ever want to go that route.
4) Conflict. A lot of the survey missions have you run into pirates, desperate scavengers down on their luck, and [REDACTED]. This game is all about conflict and space battles foremost, so this point is important.
If your looking for lore, unfortunately the best your going to get in exploration missions is the colonies you find yourself, and Unknown Skies (a mod) expands on that by adding new and interesting planet types with some cool features to some of the planets (like them being religions landmarks so you get better stability).
If your looking for a purpose, well. Vanilla doesn't add that, but in Nexerelin (mod), the planets you survey usually get colonized by the faction that put you up to the survey mission. Something that, I argue, should be in the base game to make survey missions more impactful other than "get cash and go home for more cash through survey selling".
A lot of the systems in the game could be further fleshed out but are made more "simplified" to make the main focus of the game, combat, more relevant hence why it seems kinda "empty" persay.