Mapping Data - Quality, Quantity Or Both?

In the history of mankind, society was always heavily relying on the knowledge regarding their surroundings. Maps of already known areas were used in different areas of human activity, regardless if they were military applications or for plain orientation purposes. In the modern days of the 21st century, it is almost unimaginable for any corporate or private user to carry out their usual activity without precise knowledge of their (eventually larger than before) surroundings. One thing that changed in the past few years is that although people always used maps, the making of these were in the hand of certain specialists - the land surveyor engineers. Today, to a certain extent, any user can contribute to the expansion of existing maps (or even create new ones), thus leading to a vast dataset included in these maps. While this will theoretically further expand our knowledge regarding our surroundings, a natural question can come in everybody's mind: does the increasing quantity lead to unassailable quality as well? Can we enhance the reliability of existing maps and contribute to nearly error-free future maps?