I can't say I see any qualitative difference VFD in the $1000 microwave, or the $4500 surround amp or some of the $100 gear I have. The better gear is better at protecting the VFD since they measure surrounding light levels and drops the intensity to a trickle during the night. But they are almost uniformly normally look quite good until an unused segment is lit. I kind of guess that you can't just buy more expensive phosphor to gain extra life. While it isn't the same type of phosphor as used in a CRT, we still know that even high-end CRT monitors sold for $5000-$10000 or more suffers from the phosphor efficiency fading with time.

What you can do with a VFD, is adapt the filament voltage to maintain the visible intensity as the display gets older. But it isn't easy/cheap to individually adjust the intensity for each segment. So even if an expensive VFD can compensate for loss of intensity, you can still see a clear difference in segment intensities when you light a little-used segment.

Anyway - having a timer-controlled or feedback-controlled system to increase the drive as a display gets older is used in lots of different display technologies. It is a requirement for OLED displays, since red, green and blue fades at different speed. So without correction, an OLED would not just get dimmer, but would start to show larger and larger color errors.

To the end user, it doesn't much matter if the display type can maintain the intensity because of magic physical properties, or if it can look mostly the same because of hardware correction logic. Most people don't look close enough at power consumption to consider that the fading is compensated while increasing the total power losses.