Allo there,
Have you made steam have administration access?
Certain 3rd party apps like antivirus may block downloads so maybe adding steam to the exclusion list will help.
Have you tried installing to another drive?
Does the error state which folder it's having an issue with?
Currently, it looks like its the Commons/Destiny 2 folder that's misbehaving. There's no Destiny2.exe file in there at all, when there should be, which is causing a lot of problems. Every time I download, it gives me the same issue.
I'm trying on a different server host. My current hard drive has no issues with it, as I can download, install, update and play other games on that Hard Drive no problem. If my current solution isn't working, I'm gonna try to reinstall steam. I've heard that can fix some issues.