Another EU Only Event

Why does EU keep getting these grand events that look hella fun? Why does it have to be an exclusive event? For anyone not in the know they are having an ARAM event with it's own mission line, exclusive only to EUW. Last year they got that slumber party event too. While I'm at it, OCE gets their own regional events, as does JP. At least their event make sense to be regional though, coral reef/wildlife event and cherry blossom event respectively. But why does EUW keep getting these event that have no reason to be regional? There's seemingly nothing that ties specifically to their regional or gates other regions from being able to fully understand or enjoy them.

I would also like to point out the reasoning we got last time was that somehow it makes sense to give each region it's own personal events from time to time. Which again I really don't understand for EUW. The other thing we were told was that NA would get their own exclusive regional events too, which to my knowledge, hasn't occured. So now, I want reasonable answers. Why is ARAM-ARAMA EUW exclusive, how was it decided to be regional and not worldwide? What ties it in specifically to EUW? Where is the NA exclusive event?

P.S. I really don't care about us getting a regional event, but if you're going to make what clearly seems like an event that could be global only regional, that ai got excited for and wanted to play. Then I want something just as cool for NA.