What is MSYS2?
MSYS2 isn't "one tool to rule them all", but tries to focus on what it's good at. It provides a native build environment, based on open source software, and makes you feel right at home when you are already comfortable with Linux. There are good reasons to use multiple different environments and tools for different tasks on Windows.
MSYS2 vs Other Projects
In case you'd like to see more comparisons or feel that they could be improved please let us know.
MSYS2 vs WSL
MSYS2 allows you to build native Windows programs, while with WSL you can only cross compile them which makes things more complicated. If you are just looking for Linux CLI tools, or want to build software that ends up on a Linux server anyway then WSL is the better choice.
MSYS2 vs Chocolatey
Chocolatey mainly bundles already built (open and closed source) software and makes it easy to install/update them. In MSYS2 on the other hand all packages are built from source and you can easily reproduce the builds on your machine. Chocolatey packages have the advantage that the bundled installers usually have better Windows integration, in that they set up file associations, shortcuts, etc. and because they are not built from source there are also lots of packages for closed source software like Visual Studio etc. that would be hard to manage/update otherwise.
MSYS2 vs Cygwin
The unixy tools in MSYS2 are directly based on Cygwin, so there is some overlap there. While Cygwin focuses on building Unix software on Windows as is, MSYS2 focuses on building native software built against the Windows APIs.
MSYS2 vs Arch Linux
MSYS2 and Arch Linux share the package manager and all that comes with it, like build definitions, rules for how to package things, how updates work, how packages are signed, how packages are shipped, the rolling release nature and so on. By re-using this functionality and concepts we can focus on the actual packages and profit from the experience and work of Arch Linux developers. Users already familiar with Arch Linux will also have an easier time getting started.
MSYS2 vs Scoop
Due to lack of experience with scoop see their comparison page: