During the Phoebus cartel, they intentionally reduced the lifespan of bulbs from 2,500 hours to 750-1000 hours to get consumers to buy more lightbulbs, and certain specialty lamps (like the high-intensity lamps) had an even shorter life of 500 hours.

The earliest incandescent bulbs (as in the Centennial light bulb) sometimes she a ridiculously long lifespan for example.

If I am understanding correctly, one of the surely multiple contributors to the 1000 hour limited lifespan was for efficiency. As the filament burns hotter it lasts less long, but it also gains efficiency. I believe they decided that 1000 hours with ~15 lm/W (varies) and ~2700k was a good compromise. Of course you can get 15000 hours if you settle for a horrible 10 lm/W but thats gonna be like 2200K CCT which I am sure is undesirable in many people's opinions. I could be wrong.

If you look at the Centennial Light you will see that it is barely glowing and the CCT is very low (along with efficiency of course). This is because it only uses around 4W for some reason (originally up to 60W). So yeah if you drive any 60W lamp at only 4W, it's gonna last a really really long time. But it will be more inefficient, and the CCT will be really low. This is my understanding

Pretty much exactly like that. 1000h bulbs gave a good balance between lifespan and light output. The mot common way to make a long life bulb is make one for 130 / 250V for the 120 / 230V markets respectively. under driving the lamp increases life significantly, but you get a worse quality and amount of light.

There is a saying "A candle that burns twice as bright burns for half as long". That saying is true for electric lamps too. If you put a 120V bulb on 230V, it will be really bright and much whiter than usual, but it will burn out very quickly.

https://www.youtube.com/watch?v=zb7Bs98KmnY

I hate this myth so much. Price fixing is a problem, but standardizing on 1000 hour is not.

With 1000 hour lamps, now the consumer can choose the brightest 60w lamp available with no life span penalty. Before settling on that, the consumer could buy a lamp that bright but perhaps suffer from a very short 500 hour life span, or a lamp that bright but with a huge power consumption which makes it cheaper to just buy more lamps that have higher efficiency. Even back then they were looking at efficiency.

Aside from that, extended life lamps have always been available, even in those cartel days. They were marketed as a good option for lamps that are in hard to reach places like chandeliers or high ceilings, or above stairs.

Speaking of the CENTENNIAL LAMP, their site was down for awhile a few months ago.

Recently, this lamp was celebrating its 125th anniversary!!