Resistivity doesn't account for the many ways in which oil may reach end of life. Factors such viscosity, various insolubles, TBN, TAN, % fuel, % water, etc...
I don't think a yearly Blackstone report is necessary for my vehicle (I do yearly oil changes at 12,000 miles), but I do it anyhow because I share the results on various forums and the data adds value to the community.
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