I am not intending to make light of your issues. I am just not convinced skin smoothness is the fundamental issue, and citing skin smoothness as the cause may distract from a quick solution.
Wikipedia article on touchscreens suggest that the capacitance of the bulk of your finger, not its raised ridges, are used for sensing in most smartphones today.
That article goes on to say that when sensing a fingerprint, typically the same capacitance technology is used, but the sensors are just spaced closer together. In that case, lack of readily discernible fingerprints might be an issue. But iPhone 16 does not have a fingerprint sensor.
This all suggests that except for a fingerprint sensor, the smoothness (alone) of your skin, or lack of detectable fingerprints, is unlikely to be the underlying issue.
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I second the suggestion that you contact Apple accessibility support.
They may have seen (and solved) cases with folks who have problems with touchscreens.
If no joy from the first person you speak with, ask to have a specialist contact you.