I had been playing WoW from EU launch till the summer of 2017. Legion was at the .2 patch, the content was huge and already overwhelming for my main class only.
I probably never had a chance to finish all order hall questlines, gather mounts, armor etc anyway.
Add the fact that paragon mounts were a true gamble and not a cumulative drop (i would have preferred if every paragon chest dropped a token, which, when gathered enough, could be used to buy the mounts) and my will to play died completely, as the effort felt a complete waste of time.
If i ever returned to WoW, it would be to scratch that collection itch, along with following the story. Some of those itches will never be scratched now, so, i would prefer to not go near the itch at all.