This will depend on several factors. First, off it will depend on who love iPhones and who loves Samsung phones. There are people who swear by Apple products and others who swear by Samsung products. Furthermore, the Samsung Galaxy Note 9 has been on the market now for a few months or longer and people have been buying this phone for some time. If Samsung came out with a new model it would be easier to compare the two products to see which one had the best features.
Apple is still a strong product and people still buy Apple. I know these phones are expensive, but they do last and you can keep them for years before changing. I ended up switching over to Apple and the iPhone because my family who lives in the US all use them. It makes it easier on me to talk with them on Facetime or send them a message. It doesn't cost me anything.
So if it came down to needing a new phone soon I would go back with Apple because now I am used to this phone and I love the way it is. I bought a Samsung Galaxy phone recently for my husband and there is just something about the Android software I don't like much at all. I prefer the iOS software because it is much easier to use and has a great setup.