So I suppose there already is a phone with an analogous form factor.
It just spurred the rage that we still haven't adopted metric in the US -- even after spending a good chunk of the 1970s learning it in school and being promised metric would be the new measurement standard.
In all seriousness everybody still probably needs to learn it in school, because the scientific literature is entirely in metric. Even papers authored by Americans and published by, e.g., the American Chemical Society, all use µg/mg/g/kg and µm/mm/cm/m for their measurements. If you don't have an intuitive understanding of those measurements, you can run into visualization problems.
(It wasn't even told to me that it was the default for most of the world. It was disappointing to learn later how much resistance to metric there was in the U.S.)
Moving the needle on what units people use conversationally is what's hard.
And then Reagan showed up just in time to save us from that Commie nonsense: https://en.wikipedia.org/wiki/United_States_Metric_Board