I said "very least". It may not be the solution, it is probably part of a solution(s). The various options being looked at are listed, with test results, in the DOT document.

And running the Loran-c was not that expensive:

> DHS also reported that terminating the system would save the government $36 million in fiscal 2010 and $190 million during a five-year period, according to its budget.

* https://www.nextgov.com/cio-briefing/2009/03/obama-proposes-...

For the purchase price of two F-35s the Loran-C infrastructure could (have) be run for five years.

(e)Loran is being (has been?) deployed by South Korea because of all sorts jamming around their peninsula, and it's quite robust. Russia never shut down their (Chayka) network. China is expanding their network:

* https://www.gpsworld.com/china-expanding-loran-as-gnss-backu...

> One I forgot to mention is internet-based wifi SSID geolocation lookups

Would Wifi SSIDs will be available to the aircraft flying at 50,000 feet? Which SSIDs are available to folks in their boats in the Florida Keys? Or boats in the shipping lanes in the middle of the Atlantic? Loran-C skywave propagation (especially at night) can give rough positioning at great distances. You wouldn't want to use it for an ILS approach of course.