System Properties Dialog Survives Windows 11's Cleanup Crew
Windows 11 has been gradually replacing Control Panel with Settings, but there's one exception. One control panel dialog still remains untouched by the migration to Settings.
The System Properties dialog can be accessed via the Run command or through the old Control Panel. It contains advanced settings that haven't been moved to Settings yet, including environment variables, performance options, user profiles, and startup and recovery settings.
Microsoft has been working on shifting most everyday system settings into Settings, but some specialized controls still depend on this dialog. The company hasn't explained why the System Properties dialog was left behind, but it's likely because these advanced settings are only needed by developers, administrators, or troubleshooters.