The other side of this equation that isn't talked about as much is "actually getting rest when you sleep".

A problem that became worse for me over the years was "sleeping but still being tired". This manifested for me when I started falling asleep at my desk at work, or in the middle of a conversation while I sat down.

I did all the regular things, bed same time everyday, less/no caffeine, I would even workout when I got a "sleepy spell" figuring it was downtime?

I finally saw a neurologist, got a sleep study, turned out I had restless leg syndrome. Basically running marathons in my sleep! I take a pill, and things are vastly improved.