I have both and like both. There are upsides and downsides to both, and until one of them fixes their downsides, their market share will be split. The iphone has far better apps, and the apps it does have are far better built. Games especially to me are way smoother on iphone, including touch sensitivity and graphics. iPhone's integration with other apple products is far better as well including in the cloud. If you have a macbook, airpods, etc, the way all the devices integrate with one another is seamless and painless. Photos you take on your phone will appear on your macbook effortlessly. Notes you take will automatically save and you can open them within seconds. Yes google has offerings but they're half baked compared to apple's.
On the other hand, on my Note if I take a picture I can connect to my pc and take the file off my phone and move it to my computer. If I have an iPhone, its really kind of a pain just to simply access the file system to pull a file off of it, with a file system that doesn't really play nicely with pc's. Who wants to use iTunes? The notification system SUCKS, and you don't really realize it until you use android. When you get an icon up top until you swipe it away effortlessly. iOS doesn't come close in this regard where you have to stop what you're doing, cover your whole screen with a clock that comes down holding your notifications, then scroll through a mile of notifications to see what you've missed, including hidden notifications.
At the end of the day for me, its frustrating, because each operating system has what the other one is missing. Android missing the polish and quality of the apps, and integration with other devices, and apple missing basic ability to transfer files seamlessly, or lack of freedom to use your device however you desire.
Also, forgot to mention - Samsung probably won't see any updates after 2 years, if that - and iPhone will continue to get the latest and greatest for 5-6 years minimum. iPhone also tends to have far better resale value, and will probably be worth 60-70% of its original purchase price after 2 years of paying it off, while any android phone will probably only be worth 30-40%. Definitely worth mentioning.