The thing is, we all do have to eat. You can't change supply chains overnight to be perfect.
We don't have any need to wash towels very frequently, to have more than 2 children, and to charter a specific plane to fly us and only us to a destination. You can stop all those things TODAY (if you don't already have more than 2 kids), but you can't stop eating.
Switch diets, yes, but as PP have said, total dietary changes need to be thought through on a population level. No point getting everyone eating manky quorn only to find it does just as much environmental damage.
My diet has become more veg based, but that still involves out of season produce, tinned products etc.
My gut instinct is that we'll need to undo a couple of generations worth of conditioning to reduce our diets back to local, unprocessed fruit and veg, AND meat, not the international interseasonal cuisine we've become accustomed to.