Both people have the SAME BMI. Person on the right has TWICE as much BODY FAT as the person on the left. On my last BMI check, I categorized as approaching “obesity” and yet had less than 10% body fat.
The BMI was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing “social physics”. It wasn’t updated until 1995 after pressure from the WHO and then updated here in the USA in 1998 by the NIH for universal conformity. Even now, it is nothing more than a tool for insurance companies (and now employers) to deny coverage (employment)!
BMI was originally created for life insurance companies to be able to charge people according to their risk of death. It was found that people with higher BMIs had a higher risk of death. But this only worked at a time when most people were at least somewhat active. Obviously, today there are plenty of “skinny fat” people who have “normal” BMIs. On the other hand, there are plenty of active, muscular people who have “obese” BMIs, but are healthy.