The purito report mentions that testing results are hard to replicate: diff. methodologies, errors, biases, in vivo vs. in vitro, etc.

Ex. not mentioned: Ethnicity sunburn varies w/ Caucassian more prone vs. “ppl of color” due to melanin variance (also responsible for younger look)

https://kenvuepro.com/en-us/clinical-resources/sunburn-exper...

For one, it is a US study. In Australia, anyone will get sunburnt, and moreso in summer. Going to an Australian beach at the height of the summer is akin to getting irradiated with a UV gun of epic proportions.

The article also notes the difference between the sunburn incidence rate vs sunburn severity rate:

  Those who identified as Hispanic and Black with darker skin tones (FSP V-VI) had more severe and painful sunburns compared to those who identified as White. In contrast, those who identified as Hispanic with a similar average skin tone to those who identified as Asian (FSP I-IV), reported higher sunburn incidence rates.

  68% Relative to those who identified as White, Hispanics were 68% more likely to describe sunscreen as important for health, but 2.5 times less confident in their knowledge about skin cancer. 

  Those who identified as Asian were 70% and Hispanic 79% more likely to believe the sun’s rays are the most important cause of skin cancer relative to those who identified as White. 

  24x Those who identified as Hispanic were 24 times more likely than Whites to say it is not worth getting sunburned for a tan.

I guess it would also depends on where in the world you are as well. You burn easier closer to the equator (hence different melanin expression).