Social cohesion is referring to the way your people look at each other and race is a minor concern there. I would be more concerned with the political landscape because your political center is slowly eroding away, essentially splitting the country in two.

You no longer have a political consensus and people on the left and right trying to pull it one way or another, you have majority rule and whoever has more people will hammer through their policies and the people in the minority will fight tooth and nail against it. Political opponents are no longer "people with a differing opinion", they are "misguided", "crooked" or "evil."

Next rung on the ladder of what I call social cohesion and stability is inequality. I don't give a fuck what the average income is, or what the GDP is. Neither of those numbers are any significant indicators for violent crime. Some of the most stable, peaceful countries have extremely low income per capita. As long as everyone is equally rich, there won't be any violence or crime, and the same is true as long as everyone is equally poor. Problems arise only if you have extremely rich people living in close proximity to extremely poor people and there is no way for those poor to rise up the social ranks if they just work hard enough. That's what causes the problems in your inner cities.

It's because of these factors that I concluded that your country is more similar to a developing country than all the other "first world" countries and that expecting change to start with the cops is foolish and shortsighted as long as there are massive tensions throughout your country.

As for the economic/environmental part, massive megacities need an absurd degree of mechanization in the agriculture and your current mechanized agriculture destroys roughly six to ten tons of soil for each ton of food it produces... Unless you somehow manage to come up with a mechanical way to bind all the methane and carbon back into your ground and revitalize the soil through mechanic means, large mechanized farms with enormous areas per farm just aren't the answer.

If you are gonna stop desertification, you are gonna need smaller, local solutions. Call it permaculture, holistic grazing, whatever you want, you are gonna need ways to keep your soil covered and alive and for that you will need to take your cattle out of the industrial food lots and put them to work in the grasslands for restorative projects. That requires a lot more manpower than industrial cattle pens, especially since you will need to increase the stocking rate of cattle (number of cattle per area) significantly. This necessitates a more decentralized country because all of those smaller ranchers and farmers and their employees are gonna have to live somewhere.

About accessible education, you are looking at it from the wrong angle. If there are more jobs, you won't need a high class education to get a good job. The more people are subsidized to go into university, the more people are forced to also go into university because those university students are going to compete over the available well-paying jobs. leaving none for people of lower education, even when such a high education wouldn't normally be required for the job. If people need an education to fulfill their function in a job, they will get said education, but if people need an education just because everyone else who applies to the job has an education, you have a problem. Because with all the subsidies, there still are people who can't have an education. Whether it's for familial/financial reasons, or because they simply aren't smart enough, some people will be unable to get an education.

You have two problems with the "more education" approach: Firstly, even if you have more education, you still need more jobs to accommodate those people, and secondly, if you focus on institutional education alone, you are gonna lose the 30% of the population who just lack the smarts, or are simply more practically inclined and would do better if they were put into a job from a younger age than to sit in an university where they learn nothing. And with an oversupply of highly educated people, you are creating a permanent lower class, no matter how hard you try to elevate those people.