So many comments in here just make me laugh. Seems none of you have owned a recent Android phone, or iPhone.
I just had a Note 9 for a full month. It was an awesome experience other than a few bugs and battery life. Sadly, I did return it for an Xs Max, that is the best phone I have owned even over the Note 9.
The Note 9, had issues and here they were. One was the battery life. For a 4000 mah battery, it did not last as long as it should have. At first, I did get a full day, with around 50% left. But after the first update, it dropped to 30% from 6am to 7pm. Sometimes I had to charge it up mid day just to get through the evening. Accubattey did not show any apps draining it. Android System however was draining it a bunch. The camera has a lot of freezing up issues. And this is a known issue with 15 pages of comments currently on Samsung Community forums of people having issues. I didn't notice it till I had my camera running in 4k for a few minutes and then it just started to freeze.
Also, I had worse anxiety with that device having to constantly watch the battery, and find what apps were killing it, or fixing app issues. Yes, you can customize the background and stuff, but you know what, that wasn't worth it when I spent a lot of time fixing the issues. It is similar to Windows vs Mac.
I loved the screen on the Note 9, and so do I like the Max screen. Obviously the MAx has the best screen out of all phones per displaymate. The headphone jack was nice, used it a few times. I hate the curved screen on the sides. Still had issues setting off the side bar with it.
The Max on the other hand, is a smooth experience. It is faster, battery life just kills the Note 9. I have 70% at the end of the day after the same type of usage I did with the Note 9. I have no issues with any of my Apps, and FaceID 2nd gen works great compared to the X I had. So far, I only have one complaint on the iPhone and it's the true tone gets on my nerves. I turned it off and all is good now. I do wish Apple in the mail app would allow swipe to the next message instead of the arrows at the top. Makes it easier to go between them. I have no wifi or cellular signal issues like some say they are having. Mine is stronger than my Note 9 or my work phone s9+ I have now. I get faster speeds on it than either of those.
Pick the phone you like, and I am sure it will do what you want and make you happy. But my opinion is, if you want a nice build quality, reliability, and the phone just works good at all things, the iPhone is your choice. The Note 9, or any Android phone for that matter, is for those that like to tinker and fix things or customize things all the time. That is not me as my job is in IT and I am tired of fixing things on my own stuff when I do it every day for other people.
Hope this helps some make a choice. No favoritism here, I just prefer the iPhone at this time.