Absolutely. But you can combine motivation and discipline. Over time I've made my morning exercise into "just what I do" in the morning by having discipline as best as I can. But it sure does help to have a good show or the next part of a movie to look forward to while I do it.

I feel that way as well. When I'm thinking about what I like and dislike, it just makes me procrastinate and feel miserable. Life is much more enjoyable when I think about duties I have and how to fulfill them.

That is almost guaranteed way to fail and burn out.

Nope. Burn out is an orthogonal issue and has nothing to do with discipline versus motivational techniques.

Can you expand? What's actionable about it?

It isn't, and it especially isn't for people with ADHD. "Just do it" is like "Don't be sad"

This 100%