This may work for some people but it is definitely not true for many. If you wake up at 6 or earlier, following your set of healthy lifestyle rules, you would need to be asleep by 10 at the latest.
This may be good advice if you are a low level employee at a top company, but that’s because your job is to show up and be productive.
Many self made wealthy business people understand the importance of closing deals, forming genuine connections, pontificating about business ideas and large scale change well into the night.
This may be the advice they resort to now that they are 50+ but Richard Branson and Marc Cuban surely did not become wealthy this way. They only do it now to maintain their health (as they should).