It still requires willpower, but to use a metaphor, it's much easier to travel down a well-trod path than it is to cut a new path through the jungle. Repetition and consistency establishes the path, so the willpower required to travel down it the next day is reduced over time. Establishing a pre-set time and committing to that time ahead of time removes the "will I or won't I" decision at "go time", when you're most likely to falter.
It really doesn’t remove that for everyone. Glad if it works for you.
This method requires a significant amount of executive function.
My body doesn't feel the passage of time consistently. So my mind is never prepared to switch activities when it needs to.
And there are times my brain stops working on a particular task and nothing can get it started again. It's like a leg going out, you just can't stand on it.
This isn't occasionally where habit could be picked back up. This has been a problem every day of my life.
In my experience, this has been the death of every bit advice I've gotten from a neurotypical person. A lot of them keep circling back to discipline or trying harder as a solution to a problem they can't make sense of. Lack of understanding isn't their fault, this is so far outside their frame of reference they can't make sense of it in a single conversation. Fortunately understanding isn't required, only the acceptance that other people have limits they don't have themselves.