Great Question. It made me pause. There are a lot, but I hear what you're saying.
For me; I have a deep OmniFocus database with about 15 perspectives. I can launch any of the 15, with visual icons to launch them. I can directly link to an AppleNote. I can launch a keyboard snippet.
I can Better Touch Tool, KeyBoard Maestro, Alfred, and TextExpand everything above on my keyboard without Alfred Remote.
But what Alfred Remote reminds me is that I can touch my frequently visited sites, I can choose which browser to launch from, etc. I can also launch anything from any of those apps as well.
But is AppleNotes necessary? No. But its a nice to have accessory!