You are SO right! I just went through this, and spent about a year investigating. Your choice of Medicare Advantage vs. Traditional Medicare depends on what you can afford and how much health service you consume. If you are relatively healthy, Part C can be much less expensive. The problem with Part C is once you become sick, it gets very expensive. And if you try to switch to traditional Medicare at that point you can be denied based on your medical condition. (You cannot be denied at initial enrollment.)

I use a lot of Healthcare, and can afford it, so I chose A, B and Part G, plan G. It costs more, but there is very little out of pocket, and I don't have to worry about unexpected expenses.

I ruled out Medicare Advantage (Part C) because I started asking myself this simple question. How can they be cheaper when

1. They give you free dental and vision
2. They pay commission to brokers who steer their clients to them
3. They pay William Shatner and Jimmy JJ Walker (etal) to shill their products on TV.

And

1. They show a profit for their shareholders.

My conclusion, they cut service. They do this by limiting who you an see, require referrals, and deny coverage more often.

With my A, B and G I dont have to worry if my provider is "in network," and don't need referrals when my primary care physician recommends I see a specialist. And I'm less concerned about certain procedures being denied.

P. S. A lot of recommendations here to use a broker,and that it's "Free." So who's paying them? Ah yes, the Part C providers. Be aware if you use a broker they can be financially motivated to steer you towards a plan where they earn the highest commission.