Also that even on the side quests there are nice developments in characters.
This. Contrary to many other games, most NPCs in Piranha Bytes games are memorable and their quests logically connected to their personal story. This goes way back to their first Gothic game.
*** SPOILER FOR ELEX 1 ***
One of my favourite moments in Elex was when I checked already "done" areas in the late game for any details that I might have missed, and then stumbled upon an NPCs in the Valley of the Damned (Drog) who my prior actions got banned from the Berserker village Goliet. Naturally, he blamed me for it and wanted to "settle this once and for all", but I managed to talk him (and pay 2000 shards) into going to the Clerics and start a new life. I even tried to protect him on his way, but lost sight of him during a fight with local creatures. To my pleasant surprise, I later found him again in the Cleric's cantina. In our final conversation, he told me to fuck off, which was totally fine with me, since I was the reason for his situation.
*** END OF SPOILER ***
PB games are filled to the brim with these little side stories and personal fates, and you can never be sure if the random stranger or even enemy could lead into some of them. That's why with all of their quirks and shortcomings, I passionately love every PB game, although I never play one before 1-2 years of patches. edit:
Apropos, the fact that NPCs will actually travel between locations (even across the whole world map as in the above example) and can be followed if the player manages to keep up, is an extremely immersive feature that many so-called AAA games do lack up until this day. edit 2:
As one last anecdote, my absolute favourite conversation in Gothic 2 was with a man who sits on a bench in the middle of the human village. When the main character asks him how it's going, he answers: "Ah, all quiet. I guess when the the orcs come, we'll hear it."