All of the names being bandied about seem to have extensive qualifications. If race or gender is the tipping point that decides they're to be a Supreme Court Justice does that mean the quality of the court is diminished? If so, how? The basic qualifications are still there. Ronald Reagan announced during his first campaign that if elected one of his first appointments to the court would be a woman, and he followed through with Sandra Day O'Conner. Amy Coney Barrett is on the court now because she's a woman. Does that mean that either of them are somehow less qualified than others for the job? I just don't think so.
That’s the sad part of this, whomever he picks gets an asterisk whether they deserve it or not.
Does the fact either Biden or Reagan chose or will choose a justice based on intersectionality guarantee that the chosen candidate will be less qualified? No. But does it make it more likely? Yes. If one deliberately chooses to exclude a large pool of candidates, namely, of men (for Reagan) and of women of all races except black, and men of every race (for Biden), there is a probability that a superior candidate exists but will be excluded. The probability increases the larger the excluded pool becomes, and becomes a near-certainty as the still-eligible pool shrinks to just a few people.
The only way to be sure that one appoints the most-qualified candidate is to consider the qualifications of every single candidate, with no arbitrary exclusions.
Unless, of course, your “qualifications” include who they are - i.e. you want “a nation of men, not of laws”. (Again, apologies to feminists.) Then, and only then, you appoint people based on who they are, rather than how qualified they are or how they will rule.