The backwards-compatibility stuff already in this thread is all true, but also they don’t know how to remove some things. Microsoft has wanted to entirely replace Control Panel with Settings since Windows 8 came out, but they gave up. And rewriting the whole operating system from scratch would take decades and still inevitably lose compatibility with some of the random old software mentioned here.
Windows legacy Control Panel is finally being deprecated but won't be removed anytime soon - Pureinfotech
Microsoft confirms that the Control Panel for Windows is in the official process of being deprecated, and it'll eventually be removed.
Pureinfotech • Windows 10 & Windows 11 help for humans