Good for them for taking a stand against consumerism, but their personal shopping habits (even collectively, they equal less than a drop in an ocean) aren't going to change neither climate change, nor inflation.
This idea that "every little helps" is just more of the same "personal responsibility" those who are actually responsible but refuse to be held accountable push on to the rest of the population to distract us from their own actions.
The only way to fight climate change (and be rid of the artificial concept that is inflation, which is there solely to make the rich richer) is by removing the cancer, rather than continue to apply band aids to it, and abolishing capitalism.