These are
(1) Easily available online, and various apps can save offline copies of arbitrary portions of the maps to be used without Internet access.
(2) Frequently not accurate / updated, and don't contain all hiking trails.
If you had looked up the Wikipedia article on the USGS maps, you would have seen the following:
> In 2008 the USGS abandoned traditional methods of surveying, revising, and updating topographic maps based on aerial photography and field checks. Today's U.S. Topo quadrangle (1:24,000) maps are mass-produced, using automated and semiautomated processes, with cartographic content supplied from the National GIS Database. In the two years from June 2009 to May 2011, the USGS produced nearly 40,000 maps, more than 80 maps per work day. Only about two hours of interactive work are spent on each map, mostly on text placement and final inspection; there are essentially no field checks or field inspections to confirm map details.
> While much less expensive to compile and produce, the revised digital U.S. topo maps have been criticized for a lack of accuracy and detail in comparison to older generation maps based on aerial photo surveys and field checks.
https://en.wikipedia.org/wiki/United_States_Geological_Surve...