Why are challenges called side quests?

[PickONer]

Сouldn't the developers come up with 30 little stories? For example, the kids in Seiran are playing hide and seek, why not make it part of a side quest? I think it would be sweet.

[TotemMX]

Most of developers dont know how to do good side quest. It is usually the least developed feature: useless, tedious and does not add anything to the plot.

Scarlet Nexus' side quest are not the worse, but are pretty bad.

[Dinnyforst]

I personally found it more engaging than most common fetch quests. Some are quite tricky and bit strategic.
As a linear game, there are not much creativity due to its scale and limitation, but I agree it would be nice to expand lore via side quests, because world of brainpunk is intriguing.

[PickONer]

We could help people who have no esp-ability, for example. In the main plot, very little attention is paid to them. I remember only a girl in the hospital and a little boy (you know).