Given that hair loss is genetic

It’s annoying to see people so confident that “X is genetic”. Where do you get your confidence from to make such a statement?

• https://humanmicrobiome.info/intro/#alopecia-hair-loss
• https://humanmicrobiome.info/genetics/

I was just thinking about creating a spreadsheet with people’s contact info, notes, and a picture. I guess an app would be preferable, especially if there were a web/desktop version, and it was compatible with a spreadsheet (can export from/to a spreadsheet).