I think it's a little disingenuous to try to compare high/er end Apple laptops with soldered storage to $2-300 Chromebooks and budget devices with soldered eMMC (which is much more like a CF/SD card than anything else) in your argument in the first place.
As you acknowledge. When you look at actual competitors to Apple, you're forced to acknowledge that yup, no other manufacturer solders storage.
But yes, with due pedantry, the statement that "no other laptop has a soldered SSD" is technically wrong.
You could get into additional debates on whether eMMC and eUFS would map to most people's understanding of "SSD", but...