Sleep apnea is BS? Based on what? Not believing in something does not mean it does not exist - it simply means that you do not yet fully understand the process by which sleep apnea is formed or for what purpose the breathing machine has it alleviating it. For many people, shallow/ paused or disturbed breathing keeps them awake as a build up of Co2 in the blood forces the body to wake up so that the person can manually draw in air. Having a window open will not fix this issue.
Oxygen is not the same as opening a window. Ever seen a person almost drown, be administered oxygen after becoming unconcious and being able to breathe afterward? Why is it that they didnt just let the air around them do its job? Why do hospitals administer oxygen if all they have to do is open a window?
If you have ever sought a Drs. Advice, or taken pharmaceutical drugs (paracetamol etc), followed progressive overload, trained in a specific rep range for a goal, then you have followed an outcome of a study.
In saying that, not understanding scientific process or its application does not render it void. Think of a study as a piece of a puzzle; in soft sciences, the environment in which the intervention is placed can vastly affect the way it behaves. So even though the outcome is said to be, for example "eating fat causes heart disease" it fails to take into account the plethora of variables which also influence the outcome (what was the rest of their diet, how active were they, what ia there family history etc). Most people do not actually read a study from start to finish and just take note of a one sentence conclusion which may not accurately sum up what the study actually found. So when another one sentence conclusion states the opposite, they think it renders scientific protocol void. It doesnt. Read the whole study to understand the process and its limitations and to what population it actually affects.
I do not blame you at all for mistrusting science, there is a lot of data out there that has been tampered with so that results fit a certain, preconceived trend (see: the lipid hypothesis) or reviews which only select studies (or majority of studies) which fit a certain criteria. This is why observing the data as a whole is very important as opposed to taking one study as law.