No, it's a myth:

https://www.npr.org/sections/thesalt/2015/02/10/384948585/ta...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5533136/

https://www.motherjones.com/environment/2015/11/truth-about-...

None of those mention Glucosamine. And they seem to be sour grapes articles, not sure why. One of the “myths” they dispel is “bone broth tastes good”.

It does raise some good thoughts on why it’s not a super food.

Quite probably. I am assuming that home-made methods are similar as industrial scale methods (put a bunch of chicken bones and connective tissue in a vat of water, simmer, strain).