That isn't how comparisons work though. You can't compare a 20-hour/week company with good culture to a 40-hour/week company with toxic culture. You have two variables uncontrolled in that comparison.
Compare both companies at 40 or both at 20. The good-culture-40-hour would outperform the both the good-culture-20-hour and bad-culture-40-hour so why wouldn't all companies aim for 40/hours with a good culture?
It could be argued that it is impossible to have a good culture and 40 hours, but that needs a lot of analysis.
(You are working to argue that the comparison being made isn't useful and haven't gotten there. For instance, if I was going to build a company, I'd certainly want to know what parts of a culture were important to a company that compared so well against the longer working company)
I'm saying if you have the above items checked off, then you're ahead of many, many teams. (It feels to me like 99% of teams but that's just looking out my own eyes)
Compare both companies at 40 or both at 20. The good-culture-40-hour would outperform the both the good-culture-20-hour and bad-culture-40-hour so why wouldn't all companies aim for 40/hours with a good culture?
It could be argued that it is impossible to have a good culture and 40 hours, but that needs a lot of analysis.