The only problem with that is we live on a fixed budget as I don't work since they all need varying degrees of care around the clock. We live entirely off my wife's disability and whatever assistance programs we qualify for. I have neither the time, the energy, nor the money to prepare meals for myself entirely separate from their dietary restrictions.
Each kid eats maybe a dozen things themselves, 20 for the oldest, and there's maybe 6 that overlap between them. By the time I've figured out what they're willing to eat and made it I almost zero desire to even look at food let alone prepare an entirely separate vegan meal with all of that no money I have to purchase vegan ingredients that again likely nobody but me would be able to eat.
(Edit: I should add I'm not completely against the idea of changing my own diet. It's just that by the time I'm feeding myself I'm so done with the whole thing that my "diet" is whatever I can easily shove in my food hole without fussing too much about it)