Yes, there will always be disparity, but the lowest income level has been improving in quality of life, and will likely continue to do so. Poor people still get the benefits of a house, running water, sanitation, electricity, and communications like cell phones and Internet, which they couldn't even dream of 100 years ago.
People having land doesn't matter. Land is just some dirt you can do stuff with. What matters is what's between your ears. You can use that in combination with land to grow food, build a house, or run a business, or you can use that without land to make money, run a business, rent an apartment, and live anywhere. The main mistake poor people make is that they never accumulate any assets, instead spending all their money as soon as they get it. And those assets don't have to be land. Even some stocks and binds, or just some cash in savings would do to start with.
Your kidding right. Land is all that matters. No matter if you dont have land you have nothing. I can charge you every cent you make to live on what you don't own.
You could charge it. But unless there is something supremely special about your land in particular, if you charge too much someone is going to undercut you because a little profit is always better than no profit.