The biggest problem is the false belief that success is based on merit. This leads to classism. Classism is just as bad as a caste system, but the meritocracy myth makes it harder to take down.
I would say that merit is one of a few paths to success.
Is it really a good idea to get rid of the "meritocracy myth"? Even if it's 100% true, there is something to the idea that if you put in effort and work hard, you have a better chance of being rewarded. The meritocracy myth encourages hard work.
If we lived in a society where people truly believed that that hard work, intelligence and effort had no correlation to success, then.... how does one plan their ambitions? How does one even go about trying to earn more money?
You definitely have a better chance of being rewarded if you work hard and have talent etc. But its a better chance, not a direct correlation.
The belief is that even if you have bad luck, eventually your good work and talent will get you in the position you deserve. Even in the cases where that works out, we sort of overlook decades of toil in obscurity in poverty.
The reality is that the relative success of people in the first world is almost completely dependent upon the fact that they were born into the first world.
For example, some significant percent graduate from college and enter into office jobs, which then enables them to have a home, washing machine, car, wife/husband, etc. Owning these things and marrying does determine success in a real way. The percentage is significantly greater in some countries than others. Does that mean that some countries have significantly more talented, hard workers? Or is it because overall the other country is much less wealthy, there are fewer good-paying jobs, and fewer student aid options?
This is where you run into another related issue: racism. If you pick certain browner countries and compare them to whiter countries, a large percentage of people will just say "Yup, those brown people aren't as talented and don't work as hard".
Is it really a good idea to get rid of the "meritocracy myth"? Even if it's 100% true, there is something to the idea that if you put in effort and work hard, you have a better chance of being rewarded. The meritocracy myth encourages hard work.
If we lived in a society where people truly believed that that hard work, intelligence and effort had no correlation to success, then.... how does one plan their ambitions? How does one even go about trying to earn more money?