One thing that interests me with the iPhone 13 Pro (Max) is the new macro photography mode. The Huawei Mate 20 Pro used to do the same trick: use the ultra wide lens for taking macro photos, it's one thing I miss from that phone.
Samsung were so focused on zooming with the S20 Ultra that they completely ignored close-up shots. It's impossible to get a decent close-up using normal techniques, so much so that they had to specifically introduce a "mode" that prompts you to pull back and use 2X zoom.
I'm going to need to see how it performs at greater than the 3X optical zoom. The S20 Ultra does pretty well all the way to 10X using hybrid zoom (5X is really its sweet spot) so the iPhone should be fine as the camera setup is 2 years newer.
The S22 Ultra should also be available before I'm due to upgrade so I'll be able to do a proper comparison — unless I pull the trigger early.