Re: bias.
I think it is silly to think factors like familiarity, culture and age don’t affect taste.
On the contrary, I’d think they play a key role. But taste isn’t the same as bias.
I think the fact I am familiar with Stevie Nicks plays a role in where my vote went on the vocalist game. The fact she is a woman or American, or was popular when I was a kid, in and of themselves are not. All those things are true of Madonna, and I wouldn’t be voting for her (unless she was up against some screaming guy pretending he‘s some demon)
The biggest factor is how much I like the sound of someone’s voice.