I look a the local thing because in my country's shops I can buy stuff that comes from thousands of kilometers away (I live in europe and I see quite often potatoes coming from Egypt, yep, and my country is the biggest exporter of products derived from potatoes...) Local makes sense on the fuel department.
Buying local stuff prevents me of buying non local stuff like : most exotic fruits, many fishes. Of course if I buy a pineapple that is grown in my country, it'll have a huge fuel quantity attached to it.
Buying local helps the farmer around my town. Even if it doesn't help, it sends a signal to whoever looks.
It also helps me to know the farmer, to ask questions (that's how I understood how screwed the milk market is).
It is also an exercise to learn to enjoy what's readily available and not look for novelty. And that, I assume, qualify as "imposing my view". But learning to love what's there and not always wish for more is a very important lesson in life.
People like me want less things and slower things. Everybody can do that (ie at some point in your life you'll have to accept you'll never have that sports car).
Now I use a car, an internet connection, etc. which doesn't help climate at all. It's impossible to be 100% coherent. But the little things I do, I do them to push for a change in mindset, mine first.
But the equations as to whether it's better in terms of the environment is a tricky one....
But there are some lifestyle changes that, if we could convince a large section of the population to do it, may make some real difference. Like eating less meat -- and eating less food (see https://bigthink.com/surprising-science/obesity-climate-chan... ).