Filaments experience a high inrush current on startup because their resistance is lower when they are cold. That's why incandescent bulbs often burn out on powerup, rather than in the middle of a duty cycle.
Tube filaments last a good long time though, particularly in small signal tubes.
They do not shine like light bulb filaments; they glow red.
The circuit designer also has a say in it; tube filaments can be operated over a range of currents: you can run tubes hotter or colder. In a digital application, you'd probably want to go as cold as you can get away with for longer life.
Tubes have various modes of failure in addition to burned out filaments, like "gassing out", or the cathode emission decreasing, eroding the gain. Of course, abnormal conditions like parts melting from overcurrent.
Speaking of incandescent bulbs: those are victims of planned obsolescence. A bulb can easily be made that will last 50 years; it's just not profitable because you can't charge 50 times more for it than one that burns out in a year. Once everyone has 50 year bulbs, you're out of business.
> Once everyone has 50 year bulbs, you're out of business.
This seems to have been the issue with the expensive Philips Hue LED bulbs (the ZigBee ones). We installed ours close to a decade ago, and we took them with us when we moved to a new house. I don't think I've replaced a single one yet.
Philips seems to have de-emphasized that set of bulbs in favor of cheaper models, as far as I can tell?
in the music world, variacs are used to bring old tube amplifiers up to power slowly for that reason. not after being repaired or refurbished generally, but certainly when the amp's condition is unknown. the author of tfa said his new power supplies do that automatically, which is pretty neat.
One difference is that the valves have more chance of burning out on a cold boot due to the temperature change.