There are benefits and drawbacks to each phone.
The iPhone XR is more affordable and has better battery life compared to the iPhone XS, but it's hampered by an inferior display, which looked too dim and almost sunken throughout my time with it. Apps and movies did not look good. Meanwhile, the iPhone XS has one of the best screens you'll get on any smartphone.
The iPhone XR is available in more colors than the iPhone XS, but I didn't like how the colors looked in person. Aside from the black and white colors, which are also available on the iPhone XS, the red, yellow, blue, and coral colors looked tacky on the iPhone XR.
The iPhone XR is a good phone, for sure, but most people are going to be happiest with the iPhone XS. If you have really large hands, you might like the iPhone XS Max, but it felt a bit too unwieldy for me. The iPhone XS is the perfect balance: It has a better screen than the iPhone XR, it's not as big or costly as the iPhone XS Max, it feels comfortable to hold, and it's wonderful to use.
You won't be disappointed with the iPhone XS — to me, it's the clear winner.