Can’t the detection be optional on the part of the users like do not track option in browsers?
while I fully agree with Marco, in many parts of the world, user metrics are perhaps the only solution for convincing website devs.
Also, in my specific case, many devs (in whatever part of the world) do not even realize that a blind person would want to access their website. Websites for downloading data, using online data analysis, language learning webapps, and online markdown editors come to mind.