I live a couple blocks away from Van Ness. Here's the project:
https://www.sfcta.org/projects/van-ness-improvement-project. They're moving to dedicated bus lanes, allowing the buses to load and unload safely without blocking other traffic. As with all significant projects, they've lumped in a bunch of other maintenance that has been put off for too long, like upgrading utility lines.
Construction generally blocks a lane of traffic on one side of the street, rerouting the other lanes and pedestrians, for several weeks at a time. Then they move on to the next block or to the other side of the street.
Just from a layman's perspective, it seems incredibly tricky to try to construct a housing development with that going on around it. The "bus line" construction has already put additional pressure on traffic up and down Van Ness, and it's got to be very tricky to get permits for parking spots, dumpsters, and other necessities with everything else that's going on. And anyway the city could probably just come through and close everything down for weeks or months so that they can perform another stage of "bus line" construction.
(I'm putting "bus line" in quotes because they haven't even really started on that part. This whole project is a pretty incredibly yak shave that's taking 5 years and hundreds of millions of dollars for a bus line.)