Why do people think it's the game's fault, when their ADHD kicks in, and they feel compelled to get the platinum or do 100% of the map's activities, and then complain about bloat? Not a slight on you OP, but i remember people complaining about clearing nests and similar activities in Witcher 3, when those activities aren't supposed to be chased down one after the other, but done here and there while going from A to B, at your leasure.
If the game gates main story line stuff behind that type of content, then it's a different story, but usually it's just there as a palate clenser.
Some of the best games integrate all those sidequests, but use it to either expand the story elsewhere, or as added bonuses to stuff you're already doing.
Some games literally just bloat the game with tons of quests for no reason, there's no story reason, gameplay reason, aesthetic change etc. it's just plain monotony.
It's bad design at the end of the day. Not like the inclusion of it makes the whole game bad or anything, of course, I don't know how dramatic this explanation post reads out.
I honestly don't remember how FFXV did it, because i tried to scrub that game off of my memory, but ideally an open world (rpg) game would have tiered system with some side missions having a decent amount of effort put in them, with cutscenes or at least dialogue pertaining the world building and story in a more direct way, and then a number of faster activities that have a small level of story development, but allow you to just play around with the mechanics, and are quick enough to be completed on your way to more important stuff.
Most (big budgeted) games i can think of do it like this nowadays (Witcher 3, the latest 2 Assassin's Creed, The division, Zelda BotW, GTA, Red Dead, etc).
These activities often get called bloat or "icons on a map" or checklist gameplay, but again, aren't meant to be chased one after the other like a drone, and i think are being misunderstood.
Korok Seeds are probably the best example, because finding them all gives you a (literal) shit trophy.
This is not to say that shit side missions aren't a thing, but the same can be said for shit main missions as well as shit levels/sections in linear games, and usually the problem is more about the game having bad writing in general, or the game itself having a shallow combat system and so on.
