There are just the three things that really annoy me about the way they're doing things.

The first is that none of that money is going into base infrastructure needed to support these massive buildings. The tallest building in the world doesn't have a sewer hookup. They have to pump out that massive septic tank every day with a fleet of a couple hundred trucks. That's just massively more expensive over the long run and demonstrates a lack of focus on the unsexy but necessary technology that makes skyscrapers an option. As soon as the oil money slows down the lack of a sewer will eat away at the money available to build a newer tower. Just look at the Jeddah Tower (formerly the Kingdom Tower) that may or may not be completed now because of internal politics and work stopped on the tower that was supposed to be a kilometer tall in 2017. Every year that passes makes restarting construction more technically challenging and expensive.

The second is the complete reliance on foreign design and oversight. None of those skyscrapers are different than any other skyscraper built anywhere else in the world. They could be anywhere, which means that they are nowhere mentally speaking. If the design was more reflective of the place, the millennia of history, and the people there I would be far more positive about them. The more things that are pale imitations of the "international style" the poorer the collective cultural value of architecture is and the poorer we all are for it. Investing in their people to create something new and valuable was something they consciously decided against, which makes me grumpy.

Finally, oil revenue is always temporary. Not only are we losing uses for oil but the oil fields in question have a finite quantity of oil in them. Even if selling oil remains profitable globally forever, Saudi Arabia will run out. There have been no significant finds of new oil reserves since 1989 and the Ghawar fields (5% of the world's proven reserves) seems to be tapping out early, some of the oil might actually be a layer of water thus substantially reducing the amount of oil Saudi Arabia might actually have. The worst case scenario is that Saudi Arabia is out of oil in the early 2040s. The Best case is that they run out in the late 2080s. Even with spending several hundred billion dollars on exploration you can't find something that doesn't exist, and the Vision 2030 program indicates that the Kingdom itself doesn't believe that there is much more oil to find and they need to transition away from oil to something else. My big gripe is that the "something else" they have decided upon are "the line" and giant manufactured luxury islands that lack basic infrastructure like running water and sewers rather than investing their money into basics, local culture, and something unique and enriching for humanity as a whole. I wouldn't mind if they just leaned into the Hajj I will never go on, I am just disappointed they are into geometric police states and Neo-Vegas instead of something that's actually practical and sustainable and uniquely them.