By analogy, say your goal is to eliminate income equality. In order to maximize your chances of your actions favoring that outcome, is the logical conclusion that you should find a job paying in median wage, that you spend your income in median consumption, and that you invest the remaining in median savings?

As much as we're raised to believe that being an example of the ideal you want to see will somehow manifest the necessary changes to get everyone else there, it doesn't really work that way.

Since the whole point of society is a system of reinforcing incentives to stabilize the power structures of the status quo and not engender revolution, by choosing non-participation in the destabilization of the existing order by being the most mediocre rather than playing the part at the extremes of the spectrum as parasite or exploiter, you end up perpetuating the inequality you sought to fix by more thoroughly lubricating the cogs of checks and balances.

An environmentalist's duty is to harm the Earth to their fullest lifelong potential to more thoroughly and completely kill off the humans of future generations before the Earth actually suffers beyond its capacity to repair.

Now that you got this far in reading: Poe's Law :)

Killing oneself is not nearly the same as deciding to not have children. The latter is a choice which will not harm you or your health.

The stated purpose is "reduce impact", not "avoid harm to myself".

Your logic is correct when we exclude all context and reasonable assumptions.

We could also end poverty by killing the poor.

Your analogy would be valid if someone had previously claimed that the single most effective way to end poverty is to prevent the poor from having children. Then one could explore the logical conclusions of their advice.

There are many implicit assumptions to any statement. Don’t like this wasn’t one of them.