Well, you may return back to the gold standard way into the distant future - given the horrible stuff centralized governments are doing. Digital coin is technically an alternative to gold since the chips that run cryptography utilize gold, but if the grid goes out - transactions are negatively affected. If they shell proofed a long lasting dedicated connection with wires under the ground to survive quakes/hurricanes along with power lines then you may have something possible. Doubt there’s enough incentive to do that since Covid may have put a damper on labor markets.