Obviously, much of what we are discussing comes down to subjective experience.
And I wholeheartedly agree with you, the resource grinding in ME1 and especially ME2 was not fun and hopefully will not be included. (Especially since you really could have people doing it for you. Setup a base on a new planet which automatically gives you resources).
However, I tend to remember many of the fetch quests in ME3 being unconnected, busy work that didn't impact the plot of the main story or the area.
And I know you want to limit the conversation to ME3, but I think the best examples of this are The Old Republic and Dragon Age: Inquisition.
The Old Republic is by no means a perfect game, but the questing structure had a very good narrative flow to it.
Each planet you landed on furthered your main story, but also had a planetary story arc. All of the side quests (many of which were generic fetch quests) were designed with this narrative in mind and furthered established the world.
DA:I did none of that. (Ok, that's an exaggeration, some zones were much worse than others). You went into a zone, and there was some narrative arc to the zone, but for the most part, all of the side quests were just unrelated. Race on these horses. Place flowers on this grave. Find my goat. Find these random Grey Warden artifacts. etc.
I am hoping they just spend more time making the fetch quests fit into the world, rather than just creating random ones to inflate playtimes.
First, I would say that the difference between presented categories 3 and 4 is very difficulty to objectively define at times, with ME3 being one of those cases. While majority of the fetch quests didn't directly tie in to missions, for me they tied to the general theme of the game. The whole galactic civilization is collapsing due to an assault from an unstoppable and unrelenting foe and all of these people are just trying to hold it together, with most of the fetch quests reflecting this while speaking of different values and cultures. The Volus trying to remind his people of the need for mercy and compassion at a time like this, the night club trying to find ways to keep their electricity running while flooded with refugees, the Batarian preacher speaking of his people's need to remember their strength. For me, they all speak to the larger story and thus are category three. To someone, they fail at that and are category four. Based on that, what is our standard of success then?
Second, I don't actually have an issue with speaking about other games and how they implemented fetch quests, it's more that I haven't found discussion about ME:A and DAI fetch quests really productive for two reasons, which is why I try to avoid them. And before going to the reasons, I must stress I absolutely hate majority of the side content in DAI as I've realized that for me the larger feeling left by the game after finishing was just empty content, an insane amount of filler which really doesn't make me want to play it again.
As for the reasons I dislike discussing DAI fetch quests for ME:A, first is that majority of time I've seen the discussion, somehow DAI is considered to be made by the same people than ME:A just because both were published by Bioware. Thus the discussion is not what the ME team has done before, but somehow DAI becomes the latest project of everyone and the discussion isn't that they don't want ME:A implement DAI style of fetch quests, but rather that they don't want them to continue implementing that style fetch quests. What this leads to us is rather than discussing what the ME team has actually, it becomes a discussion on what people think ME team has done. And I realize I'm probably failing to explain my hesitations here. My larger issue in the comparison, though, is that it is unnecessary, as the fetch quest system in DAI is actually really similar to ME1. Which partially makes it so baffling that DAI team went back to it since the ME team found it to be lacking, but that's different dev teams for you. So we could have this discussion as a part of the continuum, looking at how ME team handled it for different games, instead of dragging the spectre of DAI to the discussion.
By the way, I am not saying ME:A team won't go back to those types of fetch quests, I really hope they don't.