Yes .. and no

You're right there's nothing special about the bed itself. But that's also not the point. It's about exercising your "executive function" i.e the ability to think of a task, and then do it.

Many times people have good ideas but don't act on them. Ex. I should eat healthy, exercise, or study. Things that will objectively make your life better.

But there are just as many bad thoughts that stop us from acting on these good ideas. Ex. "What is the point of this", "this is a waste of time", or "I just don't feel like it".

Having a strong executive function means being able to ignore these bad thoughts and do the thing anyway.

Now I don't know if its causation or correlation, but if you can make your bed EVERY day, then you MUST have a strong executive function. Someone with a weak one couldn't do it.

Maybe is popsci voodoo. Or maybe there's a reason the military has you do it first thing every day.

It would be interesting to see an income breakdown of people that do and don't make their bed.