This
https://www.msys2.org/wiki/How-does-MSYS2-differ-from-Cygwin/
... seems to sum it up in a few short lines.
It all depends on "what you wish to do", i.e. which version of related software to use.
The end result of course depends of these.
Quoted:
MSYS2 uses Pacman (known from Arch Linux) to manage its packages and comes with three different package repositories:
msys2: Containing MSYS2-dependent software
mingw64: Containing 64-bit native Windows software (compiled with mingw-w64 x86_64 toolchain)
mingw32: Containing 32-bit native Windows software (compiled with mingw-w64 i686 toolchain)
Which one to actually use, depends on what you're trying to achieve and where you wish to use the resulting software.