If you don't believe that a system can be set up in a way that discourages certain people from trying, then sure, you can only measure the success of people who try. I don't find it plausible that there are no structural influences on whether people try to participate though.

I'm also not sure why you're bringing up "in the 2020s" as a counterargument against the idea that Theranos was not an outlier at the time it operated when it shut down in 2018.