LOST is a show that I stick up for even if I hate the Mystery Box shit in totality, since Abrahams only had his hand in the first season anyway. The thing is, most of the mystery stuff is wrapped up, its just not spelled out for the viewer explicitly. You can logic your way to most of the answers.

But also always saw LOST more as a character drama than a mystery show, and thought the ending wrapped up the characters arcs decently with a few exceptions (Sayid's ending is ass, Shannon being his one true love and not Nadia is completely bonkers, but anyway).

I wont argue post season 4 gambo being a mess obviously. I cant personally report on HOTD. '

As for origin stories. I will give the MCU credit on one front here, the fact that they decided to forgo that route with MCU Spidey entirely (or was that Sony's decision who knows). Because they were like "ok everyone knows the Uncle Ben stuff now, fuck that, lets not even show the guy". And yet some fans were actually mad at that lol. That being said it seems like the new Fantastic Four is an origin story so the lesson didnt stick.

But yeah Im just going to be pretty open with my readers that this story is going to take awhile and be more like One Piece or DC/Marvel comics shared universes and that they should just have fun with the ride. Character arcs will close, individual adventure and political arcs will close, mysteries will be solved, but theres always going to be something else going on. Or at least the scope is going to be so big that if it gets popular enough some other poor sap is going to have to put my notes together to continue/finish it lol. Like it could in theory end I just... havent gotten there yet in my preplanning yaknow? Sort of like how Oda has outright admitted he doesnt know what the One Piece actually is yet. (actually most of the core mystery arcs are in fact preplanned endings?