I'm just confused as to why your making such a big fuss over the changelings being this stories villain instead of discord. Pretty sure the reason Alivaril locked him away is because Voice fills the same role more or less.
People argued that the reason Voice didn't remove the Changelings immediately too was because they didn't "ruin stories" in the same way Discord did.
My entire argument has been that, no, Changelings do all of the same things Discord does, for better or worse, and are defeated in the same ways, from a narrative perspective.
Changelings don't cause less damage, take less to defeat, end fewer stories, taint ongoing plotlines less, or derail the plot less. So why is Voice ignoring them?
I think it would be flavorful if Voice wasn't ignoring them, but was genuinely unaware of them, because their nature and abilities fit the bill for avoiding Voice's notice, in my opinion, and it gives Voice flaws in their strengths, which up until now, they have not had.
It's like you said, Voice is functionally fulfilling the role in the story of a redeemed Discord, and that causes the same narrative problems. Having a fault that isn't part and parcel of them being an Eldritch Abomination, and instead it being a genuine fault in their strong suit, would make the story better, in my opinion. Right now, Voice erases tension. Every time there's any antagonistic element, the question is automatically asked, "Does Voice
permit this scenario to have tension?"
Voice fucking up social situations doesn't make them meaningfully fallible, because it isn't a weakness in any way unusual to what they are, and thus, it fundamentally sucks the tension out of any scene dealing with the Changelings, because the only hanging question is "Will Voice allow this to happen".
If the Changelings are genuinely dodging Voice's senses, however... That creates intrigue, tension, andd fascination. It gives hooks into lore, (Perhaps this isn't the first time Changelings have dealt with Trespassers. After all, it isn't the first time Ponies have...) It gives the Changelings an actual opportunity to shine as antagonists, because they aren't being humored, but are a genuine threat.
It does a lot of things that are good for a narrative, and the alternative, that this is all part of Voice's big plan to secretly steer Sunset into a more interesting story, and that the tension was false...
If Voice was going to do that, they could have just done the same thing to Discord. He had potential to push Sunset to new heights too, if Voice was just going to keep a finger on the scales behind the scenes anyway.
And if Voice wasn't going to do that for Discord, why would they do it for the Changelings, who, as I've explained in no uncertain terms, do the same narrative things that Discord does, and are not somehow "more beatable" than him.
