One could maintain without exaggerating, that the wheel was the most important technical invention of all time. All the more unfortunate, is the fact that apparently, it had to be invented several times. In the period around 2000 BC, the Egyptians more than likely, didn't know that the Sumerians already had the wheel around 3000 years earlier. Perhaps they didn't really know what to do with it. Like the natives of America, who reputedly, knew nothing of the wheel, right up into the 18th century.
Some say, that the wheel originated as a slice of a tree-trunk. Indeed, as you can see in picture 1, this would be completely unsuitable. Only then, when the wheel is made up of three parts (picture 2) and is given an axle, can it convert a sliding- into a rolling friction. This is why wheel bearings with rolling elements were later installed. However, first of all, wood remained the material, part of the time very attractive spokes were produced, to maintain the same firmness and at the same time save weight. Even as early as in the Roman times, the material iron came into play. An iron band was spanned around the outside of the wheel and together with some sort of lubricant, also in the hub, this made the bearings more durable. Because of the bad roads, the superstructure was sprung against the axles using leather belts.
One thing is probably certain, if people were to be transported on wheels, the comfort would indeed, be a lot worse than if they were carried in a litter (see below). It was more laborious to transport heavy loads on bad roads. Ships did the job much more efficiently and in fact, it was the railways, who, in the first half of the 19th century, for the first time, really brought the movement of heavy goods, rather than passengers, into being.
In 1846 the inflatable tyre was first invented by Robert William Thomson. Oddly enough, a railway engineer was having thoughts abut how the comfort, the rolling resistance and the noise development of carriage wheels could be improved. Presumably he had considered the application of his invention in railway coaches, they are the only ones, apart from those wheels with a thin rubber buffer-layer, where tyres were never used.