In the times of GPS, global navigation isn't reliant on this specific map projection. On a local level (City or State/Province level), where most navigation for non-experts is taking place, the chosen map projection doesn't matter that much. The people who are navigating distances where these things become relevant (pilots and ship navigators) are also expert enough to deal with most map projections. But for global issues, a map projection that actually represents land masses as they are in reality matters a lot.
Edit: I am aware about issues regarding GPS jamming. The latest tests regarding quantum navigation (which uses differences in earths gravity fiels) were working very well, so if jamming becomes a very common issue, these systems will proliferate quickly.