Oh, I'm not a defeatist. I think we can absolutely change the world for the better. I just don't think any of the methods you listed are valid methods to do it. Because they are all structurally captured to ensure that they do not produce the change you're talking about.

In America, your assessment is divorced from reality. 80% of people live in a major city. There is no way they're growing their own food or buying their food from local farmers.

As for running for office, looking at the Senate, 70% of the population is represented by only 34% of the Senators. That means 30% of the population controls 66% of the Senators. Sure, you can run for office, but you're not changing the structural reality of the way decisions get made.

You cannot source the things you need for life 100% illegally. Even if you could, just because they're illegal doesn't mean they're captured. Large amount of heroin and cocaine are produced by the US government through their black operations in places like Afghanistan, Colombia, and Southeast Asia. Illegal doesn't mean subversive.

But let's take farming. In the US, small family farms produce less than 20% of the agricultural outputs in America. There's actually no way to live off farmers markets and small farmers. Sure, you can spend some of your money there. It won't change anything though. Besides, those farmers also need to buy equipment, fertilizer, pesticides, herbicides, and seeds. Most of your money goes to the mega corporations that supply them. Family farms operate on something like 10% margins. Labor costs between 10% and 40% depending on the type of farming. So the vast majority of the money you spend with small family farms goes to the massive corporations like Monsanto, John Deere, Bayer, Cargill, and the 3 or 4 major fertilizer producers.

If you’re in a wealthier country or are a wealthier individual [...] you can change your nationality and thus who you vote for

This is also ridiculous. It's the equivalent of moving to Japan so you can get green tea kitkats. No expats in history have ever formed a voting power strong enough to change politics in the place they moved to. So yes, you can actually change your nationality so that you can cast a different ballot. It doesn't actually DO anything. It's like moving to a different cost so your tears fall into a different ocean.

Your mindset isn't optimistic, it's delusional. So of course my mindset looks defeatist to you, because I can take every single example of "power" that you think you have and demonstrate how it's not power at all. But I am an optimist because I recognize that there's far and away more of us than there are of them, and that we are capable of overcoming the psychological abuse and training they have put us through so that we fight each other and by overcoming these things we can form strong bonds between all of us and together we have the actual power to shut down their systems and build new ones that serve us.