Could also be a problem of monolithic, non-modular development. I know that's sunk some projects in the past, when they grow large enough to suddenly need a refactor because the "spaghetti" has become so tangled they can't add new stuff to it without breaking older stuff, and nobody thought to make individual portions of it removable and replaceable like parts. Like, in a level based game, if one of your level designers accidentally put a bug into it, you can just remove that level and redo it, leaving the others intact. You can add more chapters after the game's campaign for DLC. But if you do a huge open world with a bunch of quests that all take place in the same world space and all share the same resources, it can become impossible to extricate a portion of that for servicing or later inclusion unless you purposefully designed your data structures for that from the start.
I feel that this definitely is one of the big causes for delays in progress for this game, if you make solid modular components for each element it's then just filling it with useable content. To me I don't think they have this concept in mind when building any features. They just sorta implement them as they see fit, which usually ends up with a half baked buggy and
inconsistent result. I've built plugins in UE5 for some personal projects before, it's really welcoming to making components re-useable, modular and expandable so it's not like it's a constraint of the engine.
If you build a good solid foundation for all mechanics before adding all the story/paint/content shit it makes the rest of the development quicker, but idk, guess that doesn't make money in the short run.
There are also many inconsistent bugs in the UE5 build, like quests breaking, interactions bugging out or being able to control your character in certain dialogue. However, they only seem to trigger for certain objects, dialogue, etc.. which makes me think there is little consistency in how the blueprints/actors are build.
I'm hopeful that in a few years this game might actually be worth replaying for the 50th time, but there have been major/minor bugs that have been there since they launched UE5 that
still haven't been fixed and most of the existing content hasn't been polished since launch. So I might take a break for a year after finally playing the last 2 updates yesterday and realising it wasn't much different.