Windows 11 is not based on a single unified UI framework. Instead, it uses a mix of legacy Win32 components, UWP elements, modern WinUI layers, and web-based technologies like WebView2 and React.
I am reading this as MMC snap-ins and control panel. There is no other alternative to manage these settings outside of PowerShell.
Also, what idiot decided that only one settings window is allowed open at one time? Sometimes I would like to be in Windows update, power settings, Ethernet settings, and printer settings all at once.