Who is currently the most qualified person to sit on the court? And why?
That is a matter of opinion, and depends on how one values various qualifications.
Speaking for myself, the various intersectional boxes that could be checked have essentially zero value for me: race, gender or gender identity, disabled status, SES background, sexual preference, etc, because those pertain to who the person is, rather than how they will do their job. And selecting people based on who they are basically creates “a nation of men” (with apologies to feminists) rather than “a nation of laws”, and I think the merits of the latter over the former have already been hashed out, at some considerable expense, in the past.