But specifically, it's the worst one because it's unbounded (labor and materials is really costly now, but its a known cost) especially in states with heavy environment regulations or other zoning regulations. In those states, usually any one person can bring in a lawsuit alleging a lack of environment studies or alleged personal damage to slow down construction, so how much holding costs do you budget for? How much lawyer fees? How many people will bring lawsuits? You have no idea!
Most projects just don't start if they have a bracket for unbounded costs like that. So now you have fewer and fewer parties willing to take on these projects with more and more people (neighbors, bureaucrats etc.) having the bandwidth to pour over each individual project looking for an opening to sue and stop. It's a doom-loop of red-tape.
Do you think the California legislature (not the San Francisco legislature mind you) is wasting its time dealing with this, if it's "not that big of a deal" [1]. The governor ransomed the whole state budget to get this passed. Similar things happened in Minnesota. This is a huge deal.
I encourage you to read the various books laying out example after example of these issues and the background data [2], [3].
[1]: https://calmatters.org/housing/2025/06/ceqa-urban-developmen...
[2]: https://www.philipkhoward.com/the-rule-of-nobody
[3]: https://en.wikipedia.org/wiki/Abundance_(Klein_and_Thompson_...