Weren’t they superceded by LCDs not LEDs? The whole big thing with Nixies was that you could display digits but if one filament burned out (which it relatively quickly did) the whole bulb was bad and even then you had to pump power into them and use these complicated plugs.

Enter LCDs, they take ages to burn in, you can run them off a coin battery for literal years, and they’re a dozen times cheaper to make.