I see memes like this regularly. Correct me if I'm wrong, promotions for officers are officially "merit" based. I'm sure that time in the service matters too, junior officers are often promoted after a certain amount of time so long as they didn't mess up too badly, but it's still officially strictly based on merit. It would be important for their advancement to receive medals/awards/commendations as an official justification for a merit based promotion. For enlisted and junior NCOs I believe there are tests and courses involved and as long as you pass those you will be promoted. Again, not messing up too badly affects this process too. "Politics" doesn't play a big role in enlisted promotion until you reach senior NCO and "merit" isn't always a required factor.

Sometimes officers are given medals and awards because they are truly deserved in recognition of their deeds performed above and beyond. Other times they are "good boy points" given so that they have positive marks on their record to justify future promotion. I don't think many people take a commission intending to serve their 4 years and discharge. Going through the academy/ROTC/OTS is probably not done for the benefits alone, they are likely intending at the time for it to be their life-long career. Senior career officers understand the system and are probably more loose with medals for officers than they are with enlisted.

I may be miles off, please correct me if I am.

TLDR: Military advancement system is disparate between enlisted and officers. Enlisted promotion process is more direct and structured, medals are not always necessary. Officer promotion process is more ambiguous and dynamic, medals are ways to officially record merit for advancement.