Maybe, maybe not, but that doesn't really mean anything in the context of this discussion. Most of the world doesn't have decent public transportation, in part because it's difficult and expensive to create decent public transportation, and in part because public transportation isn't a great fit for where most of the people of the world live. Unless you're suggesting that everyone should be relocated to arcologies so we could all give up our cars, the fact of the matter is that public transport isn't always an option, and may not ever be an option for anyone who doesn't live in a hyperdense urban area, which most people would consider to be hell on earth (not me, but I have an affinity for big cities).

In the developed world, while there's ample examples for great public transport, I have a hard time saying what percentage of it has decent coverage (whatever that is). Maybe it's as simple as saying it's mostly shit in the US and mostly decent in Europe, with the rest of the developed world also split, so about 50/50.

Most of the world doesn't have decent public transport because most of the world is -- rapidly -- developing. In the same vein, most of the world doesn't have decent internet access (I'm not saying the two are very similar in other regards). It's a bit early to say whether the developing world will end up with decent public transport. They're certainly trying with some success. They're also acquiring cars at an astounding rate, they're going to have to do major infrastructure works at enormous cost either way, hopefully they're smart about it.

As for the rest; living without a car doesn't require anybody to live in an arcology or in a "hyperdense" urban area. Most of the world (ie >50%) already lives in an urban area. There are lots of medium-sized or even big cities that aren't hyperdense by any sensible definition of that word. I don't think most people consider it hell on earth.