I think I addressed most of your issues in my response to DFHippie above, but I think I can at least address your more specific issues. To be clear, my central issue is with putting the onus on individuals to make the difference. I don't see sufficient evidence to suggest that individual voluntary collective action is capable of making a difference in regards to global carbon emissions, and I think that communicating so is not appropriate. I see it as largely misguided virtue signalling that is largely counter productive.

>My opinion is that large-scale cultural change must start at an individual level

I formerly held this belief, but I do not hold this belief currently. As far as I've seen, large-scale cultural change appears to be most readily demonstrated through forced coercion, systematic changes to the central governments, and massive advances in technology. Its a nice idea that we can all be the change we want to see and that we can change the world that way. I haven't seen evidence of it in my lifetime. Individual collective actions in the forms of protest movements have largely failed to accomplish their goals (Seattle 99, Protests against the war in Iraq/Agh, Occupy, Hong Kong, BLM). Things aren't getting better, they're largely getting worse, and those who are predisposed to take action keep focusing on types and modes of action which are demonstrated to be ineffective (advocating for people to individually become vegetarian, as opposed to finding ways of gaining power either within or over the system). People take to these modes of action because they're accessible.

I can stop eating meat. I can recycle. I can not eat some about to go extinct fish. My argument is that individual action doesn't appear to be making any difference at all. There is effectively no reduction to the amount of carbon in the atmosphere based on the % of people who have adopted vegetarianism in the previous 60 years. Arguing that people should, as individuals, go vegetarian to protect the environment, is like arguing that we should turn a fan on while the room is on fire because its getting hot in here.