Well for one, the world demography is deeply changing with population aging everywhere but a significant lag between countries which are already greying (Japan, Europe), countries which rely heavily on immigration to keep the median age stable (the USA) and countries which are just beginning to age but have large population (India, China, Brazil).

Questions about whole population groups like these are best understood not through stereotypes or anti-stereotypes but through statistics.

I found this study [0] that examines the relationship between age and things like winning the Nobel prize or coming up with a "great invention".

Looks like there's a peak in the late 30s and that peak is slowly creeping up as the population ages.

But it might also be that you need a population of 20-year-olds to actually adopt the new inventions.

[0] https://www.kellogg.northwestern.edu/faculty/jones-ben/htm/a...

Retired people don't innovate, simply because they don't work.

Most old people don’t work and a significant portion of them can’t. If you really think an aging population doesn’t have an impact on a country overall output, I have a bridge to sell you.