My experience of Starship on Windows has been great. I'm using the Windows native builds of both Starship and git (both installed/updated via winget these days) in PowerShell.

I try to avoid emulation layers like MSYS2, as much as I'm able.

Also, yes, if git hangs on git show/git diff that sounds like an antivirus problem or a dying hard drive or the first one causing the other one.

Or just a really big git repo. Starship includes a timings command, on linux (with an annoying antivirus meddling) this is what I see against one directory:

    git_status  -   6ms  -   "[!?] "
    directory   -   4ms  -   "<redacted> "
    python      -   3ms  -   "via  v3.12.9 (.venv) "
    character   -  <1ms  -   " "
    git_branch  -  <1ms  -   "on  main "
    hostname    -  <1ms  -   "<redacted> in "

If I go in to my checked out version of the linux kernel, probably the biggest git project I've got kicking around:

    git_status  -  115ms  -   ""
    directory   -    4ms  -   "linux "
    character   -   <1ms  -   " "
    git_branch  -   <1ms  -   "on  master "
    hostname    -   <1ms  -   "<redacted> in "

That's typically the worst I see it.

I appreciate Starship also has configurable limits on those timings, too. I've almost never seen Starship hang for very long, as it will just drop the thing that is slow. I sometimes but rarely (usually just starting a new shell, but sometimes if compiling in another window/terminal) see the "[WARN] Executing command git timed out" error and the git_status won't display until the next prompt and that is usually fine.