This would probably be a dealbreaker for a lot of people. Unihertz makes small android phones that are on the thicker side, and I've been hesitant to buy one because of their girth (despite there not being any alternative small android phones on the market).
The iphone 13 is 7.65mm. The Unihertz Jelly is 16.5.
Apple hasn’t made a phone thicker than 10mm since the 3GS, and that was 12.3 (up from the original 2G’s 11.6 because of the rounded plastic back vs flat aluminum).