I think that's a different element from the one I'm talking about.

Surviving in challenging conditions does generally yield respect from others (something which doesn't just apply to old people), plus it builds character (though the quality of that character varies and is not necessarily good), thus it made sense to respect one's elders back when reaching old age was a pretty good indication that one had gone through a lot and survived, something that doesn't at all apply to most boomers from nations which were wealthy and stable during their old life or those born in wealth since such people could didn't really fought to survive and probably got where they did by coasting along.

However even the qualities needed to survive in challenging conditions aren't the same as Wisdom (they can include it, but not necessarily), both back then and now. In my experience the struggle for survival alone doesn't grant Wisdom - Wisdom requires broad life experience, and whilst age does help one to accumulate life experience, it most definitely does not automatically give it - if you've lived most of your 80 years of life in one place and with one occupation, your life experience is nowhere near that of, say, a young adult who has been force to emigrate and worked all kinds of jobs with all kinds of people.

So whilst I agree with your point about how people have respect for people based on their long year when in the present day that respect isn't really deserved because said old age doesn't correlate with certain personal qualities anymore, I think that even back when old age DID relate with such quality, it was only an indicator of Character and Experience (often in a very narrow sense) rather than actual Wisdom.