If your instinct is to be denigrate people who do things differently than you, you will never understand them. However, you get the advantage of feeling superior.
Let me say why I continue using vi. I started using vi in the early 80s, then moved to vim in the mid 90s. Even people who aren't as old at me have more than a decade of using vi/vim/nvi. Those commands that seem like a burden to remember are completely transparent to me -- that is, I don't need to think about what keystroke to hit to achieve my ends. Why should I climb another learning curve?
If you tell me to just download a vi mode for vscode, I can tell you that the basic motions work, but that last 10% cause unending grief. It is like eating pasta where every 10th noodle is actually a rock disguised to look like a noodle -- completely disruptive.
I can edit quickly when I don't need to move my hands off the keyboard. Likely your dominant hand is flopping back and forth between the mouse and the keyboard when using your gui-centric editor.
> I never understood the appeal of these command-line editors with a million commands for different edge-cases. Why not just use VSCode? It has every possible extension you already need
I'd prefer to have a few dozen composable verbs and nouns than having to research and download "a million" extensions for the edge cases.
> No need to type commands just to edit text when there's a file manager
I have no idea what you mean by this. How does a file manager edit your text?
> It has remote SSH and features for vm machines
You can do that from vim as well. vim/nvi has a plugin ecosystem too. My own philosophy is to use as few of them as I can: one (the 'matchit' feature which ships with the editor).
The final thing you are missing is that nobody uses all the commands -- they find the ones that work for them and they use them without further thought once it becomes muscle memory. If the need ever arises to learn a new command or setting, I'll get around to it when the time comes. If I learn a bunch of things and don't use them, they get quickly forgotten anyway.