I personally hate rescue in pve.
Like someone said, if you play well enough you'll only ever see it used on you for griefing, apart from some random distraction every once in a bluemoon. If you see it used on you for great effect all the time...idk, learn the mechanics maybe so you don't need the healer to yank you?
Oh and the whole "it's super fun when used between friends" except it's not. If the two persons both agree, it can be for them, but not for the rest of the group, since it's basically the equal of throwing yourself off the platform for fun. But even worse, when friends think it's fun and you don't, and they keep doing it on you regardless.
As for the whole "healers can't drag tanks through dungeons and if they do it the tank must beafk or something", I read many times here of healers using rescue to drag tanks into more enemies when they don't want to w2w. I've never seen it myself, but I don't doubt believing it.
And yeah, healers can both be trolls or not know the fight well but still think they know it better than someone else and rescue them from safe into bad. It mght be human mistake, but so is dying to a mechanic by yourself, so why is one bad and the other good?

I personally never use rescue apart from stuff like ancient flare in lota, and even then often it takes too long to find the button, target the person and use it for it to save anyone, often it just drags a corpse.
Where I really loved Rescue, it really shined, and could really save lives (and matches) was in PvP. So many times I saved people there or been saved myself, and it was really game-changing. So of course they decided to remove it. Cause healers can't have good things. Only the janky pve version which is a split of grieving/accidentally killing/saving, more a russian roulette than anything.
Of course everybody on the forums is perfect and never uses Rescue wrong and everybody they rescue is actually super bad and none of this is true and rescue is a perfect tool without flaws.