My Samsung Galaxy S6 has a thickness of 6.8mm and a 2550mAh battery that requires unglueing to replace [1].
I'd much rather carry around the extra 1.8mm for the extra repairability.
[0] https://www.gsmarena.com/samsung_i9300_galaxy_s_iii-4238.php
[1] https://www.gsmarena.com/samsung_galaxy_s6-6849.php