Meet the new boss, same as the old boss
I agree that the exchange rate between animal-welfare causes and human-related causes should not be presented as equivalent, but I also truly believe it's getting easier than ever to make less harmful food choices. Like the trade-off between level-of-effort to address the problem (basically, educating and increasing options) and the magnitude of the issue is pretty solid. At least, if you do value non-human animals and minimizing their experienced suffering. Maybe it's best solved by the market, though, as alternatives become more cost effective to produce.
I can see that vegan talking points are uncomfortable but it can be frustrating to watch all your close friends (some of which intensely love their pet dogs) eat tortured cows, pigs, or chickens every day for almost every meal, and then try to dismiss the horrors of factory farm conditions. Even though human rights take priority, that's still alarming enough that it's not worth completely banishing the topic from altruistic circles (because, those that hold these views, may not want to define Altruism purely in the context of humans and not other animals).
Other thoughts: If Effective Altruism was supposed to be an implementable (as in, money-in-the-right-places) version of regular Altruism, but then doesn't work due to reality having all kinds of disincentives, that should still mean that the general problem of finding good causes/charities is worth solving, right? Like what set of provably true statements demonstrate that a cause is worth investing in to decrease something Specific&Bad from happening, and who could be trusted to identify that criteria.
It sounds like EA has became a fancy label in the same way that you have "dolphin-safe" tuna labelling– if you see the label, it's probably likely that some dolphins have been harmed.
Effective Altruism = Family. Maybe we need to extend on that concept. It’s on the surface a closed organism defined by heritage (in various strict forms) but I see a future where maybe a concept of family becomes reality that takes its values and primacy and puts it into a form of Organisation. The Mafia is a good but flawed Version of this. I am going a little off tangent but so many people in the west get scammed nowadays with exactly that angle. Victims are trusting people they don’t know and get taken advantage off because they seem to long for some kind of family. There seems to be a deep desire so maybe it could be leveraged. Just my incoherent thoughts about how some kind of future you mention in the end could look like.