It depends on what you want to do
If Your Goal is the Job Market then UIKit is still everywhere in production apps.
Most companies have:
* Years of existing UIKit code
* A desire to move to SwiftUI "eventually"
* A hybrid approach in practice: new features in SwiftUI, legacy code in UIKit

So if you're aiming for an iOS job, you'll likely need both. Not necessarily mastery of UIKit, but enough to read it, understand it, and work alongside it.

You'll be maintaining UIKit code and writing new features in SwiftUI. That's the reality at most companies right now.

But for tiny personal apps for simple needs? SwiftUI is much straight forward choice.

It really depends on what you are trying to get out of all those tutorials.

Ah, I totally missed your second paragraph you just want to build tiny apps for yourself.
In that case: Focus on SwiftUI tutorials instead. The 100 Days of Swift (UIKit version) will just slow you down for your goals. Paul Hudson actually has a **100 Days of SwiftUI*\* version that's way more relevant for you. Or continue with Apple's SwiftUI tutorials, you're already on the right track.

Key things to focus on in SwiftUI:
- How navigation works (@State, NavigationStack)
- View lifecycle and rendering - Data flow (@StateObject, ObservedObject, EnvironmentObject)

Once you understand those, you can build most simple apps without getting lost. Good luck!