The telephoto question is something I often considered as well going into college. If taking zoomed-in photos is your primary goal, you’re going to benefit from the telephoto camera. I’m a major tech/Apple nerd and I can tell you that after testing every iPhone model released, things definitely have changed somewhat when it comes to digital zoom. This is mainly due to the Deep Fusion technology incorporated into the cameras of the newer iPhones - it works by taking and analyzing multiple photos to merge the best parts into a single image, and it does make a noticeable difference for digital zoom - I have no issues with photographing my class lecture notes. However, the iPhone 11 was the first iPhone to use Deep Fusion - so if you’re noticing that your XS takes better close-ups than your friend’s 11, I would suggest that it might not be a big enough difference in your case. Keep in mind, however, that there are MANY other features to consider before you write off the 13 or 14 (they’re actually quite similar with only minor improvement on the 14). First off, I have never tested this but read from multiple sources that Apple software disabled the 3D Touch sensor (used in iPhones 6s, 7, 8, X, and XS) and switched them to Haptic Touch which is what replaced it. If this is true then 3D Touch shouldn’t work anyway. You can confirm by testing to see if your iPhone responds to different levels of pressure to select text, open menus, etc., or if a touch of any pressure will yield the same result. The former is 3D Touch and the latter is Haptic Touch, which isn’t pressure-dependent. But about the iPhone 13: It definitely has better battery life - the entire iPhone 13 lineup is what finally bumped Apple to the top of the “best smartphones for battery life” list. I use mine heavily and I’m usually a little over 40% battery remaining by the end of a typical day (7 AM to 11 PM). The display is better and brighter, with higher resolution, the A15 Bionic chip absolutely blows away the A12 Bionic in the XS in everything from gaming to photo processing, and photos and videos are significantly better than what you’ll get on an XS or even an 11. The main camera uses a wider aperture and nearly 50% larger sensor than the iPhone 11 (which is already way bigger than the one in the XS), allowing for 87% more light gathering and much better shots using Night mode, yet another feature that the XS doesn’t have. Even little things like faster FaceID, spatial audio support in the built-in speakers, and 5G (which isn’t a big deal yet at least where I live but it will be someday) are worth considering. From your post, it sounds like you should be seriously considering a Pro model since you’re looking for a telephoto and stainless steel band - more “high end” features yet at the same time you don’t want to have to splurge on those models. I suggest you check sources such as Apple’s website for certified refurbished Pro models - they won’t be as expensive. This is how I got many of my iPhones and I have had zero complaints. The iPhones 11 and 12 Pro are still very good phones, with all the features you’re looking for and more. In addition, you may even be able to find a 13 Pro at a good price.
Hope this all helps.