Are Todo Applications a Waste of Time?

Yes, and no.

Yes, in the sense of you need a list of everything you need to do, then you need to delegate because that's too many things for one person.

No, I think that keeping your list written down/stored somewhere offloads your brain to focus more on your task at hand then remembering all you need to do.

I'd say no. For me, finding the right app has helped me stay organized. I think the key is that everything goes in it...it is my single source of truth for what I need to do.