AS I quoted, B12 hygine is a factor. Did you miss the post?
Or did you ignore it because it disproved your argrument.

And if people chose to take vegan supplements, that makes them no less
vegan.

I am not saying we should go back to bad bygene. Yet 30 years of
veganism my B12 is fine. B12 is made by bacteria. Yes, it is absorbed
into animals and it is harder to get it ona vegan diet.

"Bacteria present in the large intestine are able to synthesise B12. In
the past, it has been thought that the B12 produced by these colonic
bacteria could be absorbed and utilised by humans. However, the bacteria
produce B12 too far down the intestine for absorption to occur, B12 not
being absorbed through the colon lining.

Human faeces can contain significant B12. A study has shown that a group
of Iranian vegans obtained adequate B12 from unwashed vegetables which
had been fertilised with human manure. Faecal contamination of
vegetables and other plant foods can make a significant contribution to
dietary needs, particularly in areas where hygiene standards may be low.
This may be responsible for the lack of aneamia due to B12 deficiency in
vegan communities in developing countries"

I notice you ignore that. The ultimate source of B12 is bacteria.