From a usability standpoint, I like lightning. It fits the port easily, securely, I have a ****-ton of them.
From a practicality standard however, I'd definitely prefer USB-C. I'm a one bag traveler. Literally everything other than my iPhone and Airpods takes USB-C. I'd like to just carry two USB-C cables in my bag (one primary and one backup) and be done with it.
Back when I had a Macbook Pro + Google Pixel 4, I always enjoyed being able to unplug the macbook for a minute and top off my phone when I was situated in a conference room. Very minor thing, but it definitely was preferential than having to maintain two types of cables.
As for data transfers over the cable... not an issue for ME. I do everything via the cloud and can't remember the last time I did anything with an iPhone cable other than charge.