I've got a 12 and a 14 year old, they were toddlers once! But admittedly I didn't read the life changing magic of tidying up until they were 3 and 5 so maybe out of toddler stage.
However when my wife gave birth to our second child is when I realised that if we didn't marshall our stuff properly we could never leave the house. It was around the same time as I dispensed with about 6 trailer loads of stuff we had accrued in the first couple of years of parent hood, so even before I read the book I had started to form some of the same ideas around throwing shit out and always "resetting" everything (things like restocking the nappy bag when you arrive home, doing the dishes before starting cooking etc.)
Also:
> They have been a big help, personally
I agree. Having kids has been a bigger driver of personal development than I ever could have imagined.
I airtag everything now. Either the toddler moves it, or I chuck my keys somewhere during a defcon 1 situation. They have been a big help, personally.