And the gameplay and engine have gotten a lot better compared to previous BGS games. The worlds just weren't detained or interesting enough.

Only 4 actual companions worth talking to, all of them belonging to the main faction to pressure you into doing the story. Not enough Bethesda, you need bigger, more detailed factions and companions. In Fallout 4, you had 2x the number of companions, half of them weren't tied to one specific faction, and they all still managed to be interesting with their own opinions you had to account for before going murderhobo or betraying people.

And the environmental storytelling is extremely sparse compared to Fallout 4 and Skyrim. The curated areas needed to be bigger and more detailed, without all of the loading screens. Skyrim and Fallout 4 are most enjoyable without fast travel, but in Starfield that was not the case.

And while I'm not opposed to precedural generation, even in a BGS game within reason, it needed a lot of work here. You can't just have a single version of a facility you can randomly come across, and have all instances be exactly the same. Add variability of layout, change what clutter is around, change up what NPCs and creatures you encounter, and vary what the backstory of each station is. All of this can be done with procedural generation, but it takes work to do right.

I think one of the big things that went wrong with Starfield is that they put lots of time and effort in to building the various system improvements and additions (and they did do a good job with that), but then tried to use procedural generation as an easy button. If you talk to game devs that work with procedural generation, they will generally say to to do it well takes a similar amount of work as doing everything by hand.

If Bethesda does make a sequel to Starfield, I think they could do it very well, even with procedural generation, but they need to put a lot into building that system up to where it needs to be for a Bethesda game. And if they built it up as a long-term investment, it could benefit their other franchises. Mods have added seasons to skyrim, what if BGS built a system to procedurally change season effects on a day-by-day basis, with minor tweaks? What if they occasionally had trees in the forests of Skyrim slowly grow through stages and even fall over, making it more natural? What if the clutter in houses like food on tables vary each day? Skyrim modding already strives towards parts of this, imagine if there was proper investment to add it straight into the game engine?