Traditional encyclopedias didn't lose because of their intellectual property model, they lost because they were trying to charge money for their product, so a free as in beer competitor was able to take all their market share.

A maps data set will require constant updating and the quality of the data set will be determined by the amount of work put into it on an ongoing basis. The question is which number is bigger: the monetary value of the time people are willing to donate making contributions to openstreetmap, or the amount of money that Google makes on map ads and can therefore spend improving the data quality.