It's lack of a consistent dev team. They basically had to completely rebuild their Witcher engine to do what they wanted for Cyberpunk. They did a ton of crunch and had pretty high turnover. They lost one of their leaddevs (I think he was in charge of ai actually) and probably inherited a codebase that they knew nothing about. There were tons of tech demos that showcased features, but a lot of them were probably even buggier than the features that the game shipped with so they just cut them. The ai was probably marginally better at one point, but was causing massive performance issues due to the number of npcs in areas so they cut it and put in a placeholder so the game would run.

This game is basically the poster child for feature creep. It's just that usually you end up with more half assed features instead of just dozens of empty husks. Like there's literally a fully modeled subway system in the game that they just cut. The train stations are enterable, but there aren't any ways to get to them without doing some creative parkour. The way the street cred system works feels like it was quickly retooled from something involving the clothing system, and the implant armor makes it feel like the armor system was an afterthought.

So yeah, it was definitely just an incredibly ambitions dev team that implemented all these small demos to show to marketing who then hyped them way the fuck up only to realize later that the devs couldn't deliver, or the dev that made that feature for fired/retasked to something more critical like scripting animations or something.