The strength in MK4-MKD was more in it fleshing out character backstories and motivations but the strength of MK Trilogy was its main boss and story path which were simple enough to work. MK4 was simple too but also weak, much of it is spent fussing about who has Shinnok's Amulet and the Boss himself is no patch on Shao Kahn or Shang Tsung.
MK5 on the other hand had a lot of backstory but it was kept as stuff you learn from character tutorials, the real story was just about going to Outworld to defeat the Deadly Alliance. It's not flashy and you only learn about the end result in Deception's intro but I think it's one of the better post trilogy stories.
But what about the rest? Well strap yourselves in for a long read.
-MK6 has Onaga, who was hinted at in DA, return to rule Outworld again. You must stop him or he'll merge all the 6 realms together using the special Kamidogu. If he succeeds he will awaken the One Being and unmake reality because all of the realms are fragments of this Beings consciousness. (I was going to harp on Shujinko's Konquest but ultimately that part doesn't matter. It's just there for backstory.)
-MK7 is my least favorite because it's about a dumb hokey prophecy about beating Blaze, a previously mysterious background/secret character who is now a mindless boss-sized powerboost for anybody that beats him and saves all the realms from Armageddon. I'm not even getting into Konquest, mostly because it might not be canon.
-MK9 used timetravel to reboot itself and try to play it simple, but mashing all 3 games into one story mode along with "He must win" timeline changes led to idiotic moments. Didn't help that established canon like Mileena's backstory and who resurrects Sindel got changed.
-MKX: See MK4 but now add the introduction of the Kombat Kids, Quan and the Revenants, and Mileena vs Kotal. Shinnok the final boss only shows up at the beginning and the end because he got sucked into his own amulet. Leaving the comic for later but this is a mess.
-MK11: This one is honestly not that bad. Kronika is a crappy final boss but the goal is simple, defeat her minions, retrieve her crown, come together and beat her before she restarts history.
-MK11 Aftermath: OH BOY... turns out you needed Kronika's tiara to make a new timeline so lets send Shang Tsung, Fujin and Nightwolf back in time so they can get the crown. Oh but wouldn't you know it? They're sent back too late. So now they gotta resurrect Sindel (who was evil the whole time) to beat Cetrion to get the crown needed to fix time. But even once they have the crown we have to redo the final act again for some reason so we can have Sindel and Shao beat Kitana's Unified Outworld and so Shang can betray everyone and fight Fire God Liu who shows up near the end and you get to choose who wins.
It's all too much. MKX's Komic is just as complicated with Kamidogu, Blood Magic and Outworld Civil War but I think what made it work for the most part isn't kittelsens writing but that it's in a comic format, free of having to be told within a set amount of time.
You shove too much in an ingame story and it just gets bloated.
Aftermath gave me a mild headache just trying to recall what the plot was and wondering why they didn't deliver the crown to Liu once Fujin/Raiden had their hands on it. And for the rumors about a second DLC story? Oof, thanks but no thanks.
The only reason I like Fire God Liu's New Era is for the small hope we can go back to a simple tournament story set in the past. Hell that's what I wanted after MKX when we all thought it was going to be Heroic Outworld vs Dark Raiden's Invasion.
