Actually, it seems you are differentiating between survivalism and saving the planet while I am not. To me, they are one and the same.

Nobody is saving the planet if they can’t survive the changes on it first. So you can’t have that be the "first and only mission" or you best be prepared to get it all done in an extremely short space of time.

Further, thinking about survival with a "prepper" and only a "prepper" mindset is so far beyond ridiculous it just doesn’t even bear mentioning. No one is an island into themselves. And one person can’t know all they need to know to survive well long term.

No. When collapse happens, successful groups will be employing both strategies to a degree, but doing so without all the fringe crazy talk and thinking.

After all, even quick growing crops like lettuces take 60 days from seed to produce. That means you have to live off of 2 months of stored goods before replacements are available. Minimum. As someone else pointed out, you might be self sufficient on a homestead and have your crops fail, forcing you to survive off stores and the kindness of your neighbors. That could happen in a city too. One vertical garden serving a city block could be wiped out in a flood or other disaster. Those people, too, will survive on stores and their larger community relationship.

No. Survival thinking and save the planet thinking go hand in hand or not at all.