And let's not forget the inclusion of a Halogen in the 'gas' in the bulb - the combination and recombination of the filament material with this produces metal-halides which are redeposited on the filament prolonging its life - but only at high temperatures, which require a Quartz-glass envelope.
https://en.wikipedia.org/wiki/Haloge...#Halogen_cycle
(Hence the "Quartz Halogen" or "Quartz Iodine" headlamps of old, - and the likes of the GU10 spotlamps found in pretty much every kitchen for the last 25 years.)