Our society unfortunately uses resource scarcity to essentially "reward" being born to the "right" parents, in the "right" country - the advantage conferred by going to the right school, and your parents working jobs that allow them more time at home to help their children with education, sport, music etc means that it is very difficult for people from disadvantaged backgrounds to break through that barrier and even access the opportunities.
You look at a Boris Johnson or a Liz Truss or a Jeremy Corbyn - they are in no way competent enough to have had the opportunities that they did but they got there for having been born into the right environment.
Human nature is unfortunately also still driven by tribal instincts and so where resource is scarce - say job roles or places at university - there is unconscious bias (sometimes not so unconscious) at play in many cases which lead people to favour offering the spot to someone from a similar background to themselves
Trek shows us a world where people don't have to worry about that but you still see prejudice at play (Sisko not wanting Jake to hang out with Nog is very relatable to what is seen in the real work with parents not wanting their kid to hang out with the "wrong" people) and instances of elitism (how Nova and Red Squad see themselves above the other cadets - very Bullingdon club)