I think current livestock usage is driven by demand? I don’t think everyone needs to become strictly vegan. If every ate meat just two days a week that would have a big impact. Perfect being the enemy of the good and all that. For example if meat usage was rationed by the government WW2-style that would likely effect demand too.

You might argue that’s a ridiculous suggestion which is fair. The western world did mobilize for something that’s likely to end less of life that if we continue on our current trajectory.