Veganism is not just about consumption. It's about family reforms that do the most good.
Does being vegan mean not eating animals and other forms of consumerism, or something more? It could mean a much greater obligation.
Peter Singer has promoted consumption-based veganism, quite effectively. And at the same time he has avoided taking a position that would change family policies in a way that would benefit animals. We can summarize that approach as: "We should help animals by not eating them." But that claim fails if the intent is to, all-things-considered, help animals because the "we" in it - the unspoken norm of an unlimited right to have children which permits population growth, a norm and relations Singer tacitly accepts - does more harm to animals than changing diets does good.
That's what we might call the constitutive fallacy at play. The fallacy means Singer never accounts for the actual relations between humans and nonhumans (a random person abusing their companion animal, growth driving extinction, utility-based consumerism demeaning the nonhuman world more generally, etc.) because he never accounts for the creation of those relations.
The we in our normative ("should") claims often undoes the good we think we are promoting, whether it's preventing parents from torturing the children by removing the kids post hac rather than preventing abusive parents from having kids, undoing climate progress by promoting population growth, or undoing equity by not leveling the playing field for all kids in the key stages of their birth and development.
But the fallacy does something more insidious. It robs us of our freedom, or relative self-determination.
When we create people we are also creating the fundamental power relations between them, and between them and their otherwise nonhuman ecologies, and in a way that precedes written constitutions or other binding sets of rules. If we want justice, bottom-up in the style of true democracy, just creation must come first. Imagine this process as a sort of "first election" - the one that means we all consent to be a "we" then capable of doing things like electing officials. And that mistake - not requiring things like the Children's Convention standard in family planning policies to improve those relations, which would physically constitute just communities - does more than just harm animals.
It fundamentally permits anthropocentric changes that cause irrefutable harm to all, against an absolute standard like infant health.
Think of it this way: The same growth and intergenerational inequity that degraded the ability of democracies to represent their people and respond to the climate crisis also undid much of the progress in emissions reduction that was attempted. We failed because we were not constituted, on many levels, to respond. Singer's failure arises from focusing on welfare outcomes, rather than the antecedent power relations - the rules - that first define those systems. In democracy rules should imply agreement, which implies consent, which implies freedom.
We are prone to think of veganism in terms of consumption rather than liberating total revolution because, as the constant refrain in most media that low fertility rates herald an economic baby bust, we were created (via family norms and policies most we will never see or understand) for economic growth systems - shopping malls, not town halls. We are urged to change the world by altering consumption, not power relations, because we have no real political power as evidenced by things like the paradox of voting.
Backwards family policies fundamentally drive things like extinction, growing levels of birth-based inequity, rising numbers of unhoused persons, the exacerbation of the conditions that drive pandemics, a multiplying of climate impacts on multiple levels, and the degrading systems of participatory democracy. And yet these policies are easily reversible and with policies that actually liberate humans and animals alike by using wealth from the top to incentivize delays in parenting pegged to objective standards of parental readiness, redistribution of wealth between rich and poor kids, and a universal ethic of smaller families, all of which create functional democracies.
Don't confuse chaos with freedom. Truly free people will fundamentally limit and decentralize the power (including subtle power like climate emissions, the impact of bad parenting on communities, massive disparities of wealth, etc.) others have over them, and by all means effective. And that limiting starts with who is born into our societies, and the degree to which we actually empower them. Free people - on both ends of that creation - will condition their obligation to follow the law on their actually being empowered, assessed via a simple inversion test, in functional democracies.
And we can start empowering people by overriding property rights - which are contingent on our constituting democracies where we are actually empowered - in order to obtain the resources to fund better family planning.
The solution to the constitutive fallacy is holding ourselves at optimal population ranges, which if we use Fair Start modeling will ideally reflect just power relations, at the same time.