OP seems to think not only that good parenting can beat external social influences, but that perfect parenting is simply a matter of deciding to be perfect. OP probably blames parents for all negative psychological outcomes for children: “It's not ‘caused’ by the culture or the environment, but by parenting”.
If you have a deep sense that you matter and that your value to society comes from who you are, then people being shitty to you because you’re short and the wrong shade won’t prevent you from showing up and taking up space.
It’s called _self_ esteem.
Case in point the Queen Elizabeth died at 96 but given her quality of life in terms of novelty and free luxury stuff of the highest kind (and in all realms ranging from mansions to yachts to castles to planes to jewelery) she lived like 2000 years of a regular person life. All that because she was liked by millions of people (or the institution of monarchy is)
Being liked by others is the only thing that matters for quality of life purposes, if you aren't then feeling shitty is a safety mechanism which promopts you to action and to pursue likeability to get some quality of life and not waste the precious little time that you have been given.