I'm a visual person. I like seeing images to help me find my way through a bunch of files, and I like structure -- things to be visually organized.
Evernote's true power is in the fact that it'll accept anything you throw at it (pain text, an attachment of any kind, a screen shot, a web clip, and audio file etc etc). And you can put all of this together into a single "note".
It's not always the case, but let's say I buy a lawnmower this summer. In a single note I can store a scan of the receipt, the instruction manual, a photo of the serial number, the URL to the manufacturer's website, and any extended warranty information.
You can house all that in Obsidian or Dropbox, but Evernote makes getting all of those media types into your note easy, and that's huge. I realize apps like Devonthink and Joplin likely provide the same kinds of functionality, but to me, this it the biggest EN selling point.
Whenever I think "oh, I'll just use OneNote" or "Apple Notes should work", they usually work fine for a while and then something like my new lawnmower comes along and I realize "this was much easier in Evernote", so back I come.
I will say I've been dabbling in Obsidian, but despite it's amazing power, my lawnmower example wouldn't be implemented quite as well as in EN.
But EN is a bit sluggish.
Perhaps our beloved elephant is a jack of all trades, master of none.