Why does Windows still include so many shells and PowerShell versions?

The 32-bit entries exist for compatibility with 32-bit applications and modules, especially on systems where administrative tools or deployment software still run in a 32-bit process. PowerShell 7 is optional and does not ship as the built-in Windows PowerShell replacement. ISE is deprecated, and on many clean installations it is no longer included, although upgrades can preserve it.

Several items in the list are different things rather than multiple versions of the same shell. CMD and PowerShell are command interpreters, WSL provides a Linux environment, ISE is an old scripting editor, and Terminal is a window and tab host. Terminal was designed to let you run all of those environments in one interface, not to replace them. You can configure Terminal to open PowerShell 7 by default and remove unwanted profiles from its settings.

The main reason is backward compatibility. CMD and Windows PowerShell 5.1 are still used by installers, scheduled tasks, recovery tools, enterprise software, and years of administrative scripts. Removing them could break a huge amount of existing infrastructure. PowerShell 7 is a separate, cross-platform product built on modern .NET, while 5.1 is tied to Windows and the older .NET Framework, so they cannot simply be swapped without breaking compatibility.

There is a legitimate UX complaint here: Search and the Start menu do a poor job of showing which entry is the recommended one. But that is separate from the technical reason the components remain installed. Microsoft generally avoids removing long-standing system tools because Windows has to support old business software for decades. Depending on the component, you can uninstall ISE or WSL, remove Terminal profiles, and set PowerShell 7 as the default, but completely removing 5.1 or CMD is risky and unsupported for systems that depend on them.