This has been initially reported as a Git for Windows issue:
https://github.com/git-for-windows/git/issues/4459

But it has been tracked down to originate in the Cygwin project (see
https://github.com/git-for-windows/git/issues/4459#issuecomment-1580526636
and maybe
https://github.com/git-for-windows/git/issues/4459#issuecomment-1602566700).

Using 3.4.6.1 (from
http://mirrors.kernel.org/sourceware/cygwin/x86_64/release/cygwin/cygwin-3.4.6-1-src.tar.xz),
running any program from /usr/bin takes at least 20 seconds, for example

$ .\ldd.exe --version
ldd (cygwin) 3.4.6
Print shared library dependencies
Copyright (C) 2009 - 2023 Chris Faylor
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ Measure-Command { .\ldd.exe --help }
Days              : 0
Hours             : 0
Minutes           : 0
Seconds           : 22
Milliseconds      : 552
Ticks             : 225529747
TotalDays         : 0.000261029799768519
TotalHours        : 0.00626471519444444
TotalMinutes      : 0.375882911666667
TotalSeconds      : 22.5529747
TotalMilliseconds : 22552.9747

I have also tried this with 3.4.7 - same issue.

Using 3.1.7 there is no slow down. I haven't tried any versions between
3.1.7 and 3.4.7 yet, but I can do that.

I'm running Windows 10 21H2 (19044.3086).