It’s weird, because they absolutely need to switch things up… but also they have a winning formula and so long as the games sell they will never adapt.
For me, the biggest fault isn’t the tech itself (at least not directly), but the game design. Every time they strap another system to that Frankenstein’s monster of an engine, those systems need to be justified in gameplay, which is harder to do the more there are. As everything grows in scale and scope, each component, whether locations or mechanics, feels less individually compelling. Then they hide mechanics behind the tech tree, which solves one issue by focusing the player experience, but now the quests feel even more bland because they need to appeal to every possible build.