1 is that it was heralded as being this massive intricate space game with a near endless things to do.
2 is that it was heralded as being the first of Version 2 of Bethesdas game engine.
1 turned out to be a play with words as while there is quite a bit to do in the game, barely any of it is captivating as it's even less deep than most things you do in Skyrim and FO4, but it's kinda true as the game creates an NG+ loop where your gameworld resets whenever you do the main quest (which you can do in a rather short time) which results in a virtually infinite things to do, as you get to redo the same content over and over and over.
The NG+ loop also makes it so that no matter what you do in the game feels like it's an utter waste of time. As you will reset it after finishing the main quest and don't have the ability to go back to universes you've already interacted with.
2 turned out to be utter bullshit as the engine has all the same bugs it has had since Morrowind, no new features to speak of (some say the ability to load more planets and generating those small landing areas is new, but you could load DLC maps in their engine going back as far as Morrowind and the procedural generation of the landing areas is very barebones and done better in ARGP and other games going back 25 years) and the engine only has a couple graphics features tacked on that FO4 didn't have yet.
And I mean tacked on, the new graphics capabilities aren't really integrated in the engine, just tacked onto it with ductape and superglue from external APIs.
What their version 2 of the engine needed was an actual ground up rework of the graphics pipeline to integrate natively all the crap they tacked onto it since Morrowind.
This while the new version of the engine also reduced a ton of modding features that made all their previous games so great, to be extremely watered down and some ultimately useless, meaning that it'll take even more time for mod authors to bypass Bethesdas programming to integrate features the old games already had.
Added, it took all of a week for a modder to add XeSS, DLSS and FSR into Starfield, which should've been part of the game out of the box.
And it took Bethesda 2+ months to integrate these same features themselves.