Zero sum game that requires my own death to achieve - seems a reasonable request compared to a request to not participate in the forcible birthing of billions of animals into exploitative confinement until they are killed at our convenience for eternity, or the unecessary trawling of trillions of them.

Or we can seek to achieve what is possible, and work out what isn't over time. You describe a technical problem. That aside can you even empirically prove that more animals die in agricultural fields than in nature? I'm all in favor of reducing those deaths but is it actually any worse than if we let the existing fields reforest? I don't see your point as analogous to my own concerns.

No one is. A lot of people who are preferring a plant based diet due to moral reasons are well aware of such "roadkill".

Thing is, we're not breeding them into existence. These deaths are accidental and if there were a technical solution to the problem everyone would be in favour of that. In the animal industry on the other hand everything is intentional. Both, the scale and the moral intentions are a completely different world there.

So, from the moral stand point of veganism: is it bad to kill animals? Yes. Is it worse to kill animals intentionally on an industrial scale, which could be prevented, than accidentally on a much smaller scale during plant farming where it currently can not be prevented? Absolutely, yes.

And 1.3 million people are killed by cars every year. It's a fucking bloodbath. So driving a car is similar to intentionally murdering people, of course. Don't pretend you are innocent if you drive a car.