I’m pretty sure thanks to these databases now they can identify 60% of the public with DNA samples already provided.
23 and me doesn’t make mhm it’s money from telling you your DNA, it does from selling it to the Government and Corporations.
No sense in worrying about things out of our hands. You can decide not to get a test but if one of your close family members does, they got you.
An easier task may be to avoid doing anything that forces you to worry about any DNA left at a crime scene... :(