What are the distinguishing features on a phone these days? The S10 has a better camera system, better and larger screen -- without being a larger phone, so the S10 has a better screen to body ratio, more RAM, 8-core CPU, more base storage, fingerprint sensor under the screen, dual sim cards without resorting to apple's eSim cop-out which doesn't seem well supported. The galaxy is about 1/8th lighter despite having a larger battery. No notch and less elongated screen for even more screen real estate (which is exacerbated on the iPhone by the notch). A headphone jack (and since you're free to use wireless headphones and the S10 is waterproof, there is zero reason to say not having a headphone jack is better in any way). A mircoSD slot (and same point, if you don't like it, don't use it).
And the S10 is significantly cheaper.
And before the fanatics start calling me a Samsung shill, let me be clear I don't like Samsung or Android -- the privacy and data protection issues are much more important than features imo. My current phone is an iPhone XR, and I wouldn't recommend Android to anyone. But it's very important for Apple users to understand just where Apple stands and how low-quality and behind the times their overpriced phones really way.
First off, I find the camera systems on all of these phones to be really overrated. I can't remember the last time someone on any system sent me a photo that just blew me away. The photos I took with my iPhone 6 5 years ago hold up very well with the photos I take with my X or the photos my Galaxy or Pixel friends send me. It's not like the early teens when the cameras were making huge leaps every year. So maybe they've figured out some way of taking photos that's way better than the photos everyone else is taking or more likely they're just doing the same incremental improvements reviewers and commenters often overhype. (And of course, in 6 months Apple will come out with a camera system that if trends hold, will be incrementally better than the Galaxy phones.)
The screen to body ratio is really incredibly slight and I would say overblown (if it was such a big deal Galaxy and Note phones would have flown off the shelves last year.) I'd also add that once you put a case on your phone, even those differences pretty much disappear. The S10 has an 8 core processor, which according to some testing I saw tonight gives it a slight edge when it comes to multi core processing vs last year's A12 but it's still far behind in single core processing. I don't really see where the RAM offers it much of a meaningful advantage in real use. Being lighter is nice, but in real terms, you're talking about less than an ounce. How many people in this country at least care about dual sim card readers? I don't really have any problems with the notch, and I personally prefer it to Samsung's hole which of course also limits the amount of usable space on the phone as they have to come up with ways of hiding that.
Samsung is part of a dwindling group of high end phone companies that still support a headphone jack and so I imagine the number of people who really care about that is a dwindling number. Most people I know use whatever headphones come with their phones.
I honestly don't see where anyone who's used Face ID would rather have a fingerprint sensor.
The XR pretty much costs the same as the base S10. I know a lot of people want to dump on the XR's screen, but I know lots of people with XRs and their screens look pretty much as good as my X screen. The Apple phones seem to be around $100 more than the Galaxy phones, but while that seems significant, I think it was a bigger difference back when people were trading in their phones every 1-2 years. Given the fact that Apple can be expected to support an iPhone for up to 6 years versus God knows how long for a Galaxy, one could make a strong argument the iPhone is less expensive.
2-3 years ago there was a yawning gap between the hardware of an iPhone and the top Samsung phones. That gap is mostly if not entirely gone now though I'm sure lots of Android sheep will jump on me over this. Much of the edge this phone has is due to the fact that it's 6 months newer than the iPhone models are.
The big thing about all of these phones is the big phones are all really pretty terrific hardware wise with few meaningful differences between them. Apple will probably at some point have to come down in price, but so will Samsung, Google, and all of the other high end phone makers.