Needs change too. Growing up, there was a family of vegans a few blocks away from me. Mother and three kids were all vegan. This was back in the early 1980s.
There wasn’t as much support for the extreme vegetarianism as there is now but they did ok.
But, one day the son who I was friends with, was very unhappy. She had some medical scares and the doctor was like, “Lady, eat some kind of meat – your diet is killing you here.”
So, she incorporated fish into her diet – the lowest level animal she could manage.
Her three kids, two teenagers and one kid, all remained vegan and she cooked vegan for them, but she had to regretfully have fish with her meals but it did the trick.
I’m sure nowadays there’d be more support though and she’d be able to remain vegan.