The settings app is meant to replace control panel, but they keep control panel around so that people don't complain about them changing things.
And yet people still complain about them changing things.
It's almost like they knew that the Settings app sucks. Actually, it's probably okay, but I'd still rather use the control panel. They probably would have been better off removing the Control Panel from the start rather than leaving us with a mostly useful but slightly gimped version.
I just hate how everything in the settings app looks the same. There's no color to the icons. It looks more modern and minimalist, but the unique designs of each icon in the Control Panel helped me remember them.
Edit: Everything looking the same extends to the fairly uniform layouts and window size that the Settings app uses as well. The Control Panel had all kinds of different window layouts and other windows and programs popping up depending on what you selected. You could argue that's objectively "bad" design, but it made it easy to familiarize yourself with all the functions and if you opened something up you could tell if you had the right thing just by the window layout. The Settings app makes you actually read through all the particular settings you just opened in order to tell if you're in the right place.
The settings app represents about 90% of what the common user is going to mess with. Anything not in the settings app most people aren't going to mess with unless they are an advanced user (who would prefer the control panel anyways). It is minimalist and modern because that is what most users know nowadays. Show a person who is used to doing everything in iOS or Android the control panel and they are going to get overwhelmed by how complected it is. ---
I am a senior software engineer. If you see me post here, I am tired of writing TPS reports.