The 9-5 is doing a major part of that comment. Irregular sleep isn’t the end of the world if you can sleep in and recover. Modern parents don’t get a chance to recover.
To be fair, if you have other kids you don’t exactly get to just sleep in and recover either.
Or take a nap during the day while some of the others watch your kid...
When I work from home and have a bad night, a 20-30 minute power nap during the day does wonders.