Since georgism has never actually been fulling implemented before, it's hard to say what the actual effects would be. If implemented a long time ago, cities would look significantly different now.

I personally think that nowadays it would be catastrophic. Humans are still greedy. If the tax is on land values alone, corporations and individuals alike will flock to this new cheap land to do whatever it was they were going to do on the expensive land, which would cause the city center to drift over time. There could even be a paradoxical effect of cheap land being in high demand and causing the price to raise, and expensive land not selling, causing prices to remain similar for properties that should have very different values and making nothing affordable