We don't need to give up modern amenities in order to drastically reduce our ecological footprint.
But just look at your argument for a second. Even if what you said was true, you're talking like giving up some niceties is a bigger deal that
giving up your literal life.
Buying gold. Eating a diet full of cheap meat. Replacing all your consumer electronics regularly. Traveling by plane on the spur of the moment, or flying cross-country or internationally multiple times a year. Owning a huge gaz-guzzling car because you like the performance and it's "convenient" rather than a significantly more efficient and less resource-heavy vehicle. Owning 2-3 vehicles in the household. Living in a 2000 sq ft home instead of a 1000 sq ft home. Reducing our consumption of a shytload of things we don't actually need. And on and on.
We could alter our lifestyle in a manner that could reduce our ecological footprint by a factor of 4x or 5x without giving up any "modern amenities", just by scaling back what are largely some very recent developments. We don't need to scale back 200x and become Ethiopians. If we backed up 4x it would make a huge difference, if we backed up 10x (still using 20x as much resource as an average Ethiopian) it would probably save the world as we know it.
Do you realize how completely ridiculous it would be to decrease world population by 4x or 5x?
But sure, keep on keeping on. We know where it leads.