I used to be opposed to working in the defense industry. Based on my experiences, I have reached the conclusion that the only ethical outcome is the extinction of humanity before we make this planet uninhabitable for all other life. The sooner the better. Maybe raccoons won't have billionaires, fascists, microplastics, etc. We should give them that chance. That's why I work for a defense contractor now.
The better methods will never happen completely. Even in the midst of the abhorrent east African famines of the 1980s, people were still reproducing. The billionaires want us to breed more wage slaves until the petri dish is full and no more resources exist. Our natural inclination to kill each other just needs some more effective fuel.
The outcome is inevitable, I would just like to accelerate it and try to leave something for the nonhumans.
Make birth control free worldwide and it will at least significantly decrease population growth, maybe even reverse it. Depopulation shouldn't involve suffering.