I'm gonna be honest...
I didn't care about the main story lines of Morrowind, Oblivion, Skyrim, Fallout 3, or Starfield. In fact, the one in Skyrim I never even finished. I have probably 1k+ hours logged in the game (not literally logged thanks to SKSE), if not more, but I always get too bored to even bother with the whole Dragonborn shtick or even the two political sides of the war, which also both suck ass. Like, I can of course sympathize with the people there getting invaded, but they're also such damn xenophobic assholes that they immediately lose me when it comes to support them.
For Morrowind I don't even know if there was much of a plot. I remember the boss in the volcano but not really what led up to it. F3 I completely forgot pretty much all of it so that was probably also not that interesting. I think Oblivion was kinda okay but also not super memorable - at least it had a dragon which gets brownie points from me. I tried getting into NV at some point but the performance on modern hardware was so bad and the beginning so boring that I couldn't be arsed to continue.
It's pretty much 80% open world + mods that make those games for me, not the lame ass plots. So if it weren't for the mod support, I'd probably not even buy the games at all and I just can't believe anyone who claims anything else about the other games storylines.