I think a lot about redundancy. In the airplane my redundancy is an IFR GPS backed up by a VFR (portable) GPS. That gives me redundancy against failure of one piece of equipment and also redundancy against an electrical failure. I also have VHF nav capability as redundancy against the failure of GPS as a navigational service. That could be due to military dithering, or a computer glitch at headquarters that takes down the network, or a solar flare. Something external like that.
One time, back in the day before I had a GPS in the panel, I borrowed a Garmin portable from a friend but I forgot to borrow the antenna. So I put the unit in simulator mode and put the “airplane” roughly on my heading at roughly my speed, and the map display was great for situational awareness. So I can attest that the GPS map and database was useful on a night VFR cross country flight, even without being the primary means of navigation.
I suppose I look at VHF nav the way I look at the vacuum system. The “differentness” of it makes for good redundancy.