And it very well couldn't. Slapping medical name to everything is not a solution either. Sometimes sleep disorder is as little as the wrong diet.

Sometimes people are speaking from direct experience with well-validated medical conditions fucking up their lives for multiple decades until someone eventually bothered to actually order the relevant diagnostic test.

Like sleep apnea: A lot of doctors mistakenly think that only overweight people can have sleep apnea.

I am 6' 150 lbs and was tired my whole life until I INSISTED I get a sleep study. Turns out I had severe sleep apnea.

And the solution is to sleep with a CPAP? Could I just rent one and check if I wake up more rested? Does snoring correlate with sleep apnea?

Snoring definitely correlates with apnea (your airway is already narrowing enough to "snore"). You could rent one but you wouldn't know the optimal pressure settings without a titration sleep study. You could try renting an auto adjusting machine and set the window wide open so that min pressure is the lowest possible value and Max pressure is the highest. Then if you look at the data and see that the machine had to increase the pressure while you slept with it on, you know you had a disordered breathing event(s). The machine reports back AHI but it really means that you stopped breathing and the machine couldn't treat you effectively because the pressure wasn't set correctly, but it doesn't report apneas that you would have had without wearing the machine to begin with because at pressure, it has no way of knowing/measuring them, if that makes sense.

Obviously people should discuss any sleep issue with their Primary. However, it doesn't hurt to look at habits that may be affecting sleep.