The good thing about Dolphin is you can have the real tree following your navigation. Want to go up a few levels, just click once, directly where you want to go next. None of this up, up, up nonsense. Great for snooping in many different folders in quick succession.
I install graphical and visual design apps. And I’ll navigate to the category by mouse. I don’t memorise the names of all my apps. I’m not in IT, and I’m not working with text all the time. I’ll right click the app icon and go ‘Add to favourites’, so I have a highly productive, 1 click access to important apps. I’m interested in usability, am not a beginner and I know my UI and settings well. I can see why people find this tiny green dot useful. It’s OK if you are not into usability. But note that there are many different user types, with different needs at different times. And the flexibility of KDE Plasma makes it a really great desktop environment.