Every once in a while a clown like Greta Thunberg emerges touting developing countries(60%+ of the world) to stop trying to get developed and shut down their industries, go back to stone age. Such countries obviously give them the middle finger and move on.
Switching from archaic fossil fuels to renewable energy is the opposite of stopping development.
Today it is much more cost efficient to rely renewable energy.
I think you're only referring to her 'green lifestyle', like sailing to USA, and having people use trains instead of airplanes when they don't need to fly, etc?
That's missing the point of the message.
It's not to get everyone to do that, but to have the ones in power reduce carbon emissions to the point where they wouldn't feel the need to do that.