I believe it was a mistake to decommission eLORAN (both US and Europe), for the reasons you mention. Thankfully we still have terrestrial frequency and time standards (although there was talk of shutting down WWV).

Now that the UK has been kicked out of Galileo, perhaps the government might think about reinstating eLORAN, it would be a good use for some the Longwave AM broadcast infrastructure that will be surplus in the next 10 years or so.