It is not a matter of diversity itself as much as having common threads shared by all which bind the society together enough to properly function. That has been lost and community does not exist anymore. I do not even know what it is because I had no exposure to it - only what I was told about and some tried to create and / or save.
We went TOO far fighting against the evils of conformity and uniformity of the 50s-60s but the fight was necessary. It just went too far.
While local communities and parents HAD more input into education in the past, there was a lot of uniformity in other ways.
Uniform public education is a safe way to create common threads --- even the private schools were more uniform in the past (despite marketing to justify the added expense.) Every child; ethics used to be taught; civics used to be taught to everybody; the constitution actually studied instead of a little history around it and memorize the preamble. Everybody should read 1984 too. Certain books at certain grades for EVERBODY even private schools. Other counties doing better do this. Hell, some force kids to read books over the summer-- classical books. We used to ALLOW children to fail now we screw up the whole system because of them... parents are getting too much input ; the WRONG kind of input. Parents who neglect their kids in the important ways are right there to demand and blame the schools and force changes that make everything worse. In the past parents were involved differently with education but had to accept their brat was failing and take some responsibility... maybe actually punish the kid. Parenting of kids is the BIGGEST influence and that isn't done much today in between both parents working. "Success" also means different things today as well. If we as a society valued community if we could figure out what that even is.... we would consider success as including a common experience in education. So everybody had the basics.... but even that is a problem today where basic facts and reality can't even be shared in common.
- ZONING - we don't have diversity in our communities. A small town had drunks, poor, rich, etc. they would interact to some degree -- sure racial boundaries were stronger but you still had communities within those boundaries. Now we don't even have a community within the groups we identify with.
-LAWYERS - it should be as shameful as a prostitute and as likely to be elected to office.
REALITY: WE CAN NOT GROW FOREVER. Human intelligence has severe limitations we dare not admit. Resources are limited. You can not birth your way to success. Necessary jobs are extremely limited; that is why we created consumerism and promote fashion and those too are limited (at best growth until resource limits are reached, some are logically capped, such as popular art.) A.I. will eventually remove ALL necessary jobs, but far before that point it will remove most jobs. A.I. will also remove the need for cheap labor; so the idea of a large peasant class is out dated; they will need to be culled significantly. (I don't think nice solutions to this will prevail when sociopaths are so well rewarded in our societies.)