This is one of those topics that can get heated, so in the interest of not arguing with anyone, I will share my thoughts then try not to reply again.
These topics are very troubling.
There are a huge amount of people on this planet.
Those of us in first world countries, bless our luck, have a tendency to want. And want a lot.
Anytime you combine wanting a product quick, "easy", and cheap, something is going to suffer. Unfortunately it's almost always other people or animals. Our general goods cause suffering in other countries very often (electronics, clothes, etc), while our food causes critters to suffer. There's no perfect solution. It's all much more complex, the more you learn about it, and the more you try to find ways to abate the suffering. The more you look into something like this, the more you realize that it's way more complex, and interconnected than you realize. It comes with a feeling of powerlessness.
Along these lines, I have always noticed that trying to force people into complying with a solution has been rough. People push back against the forced changes and it's a mess. I guess, I find the best thing I can possibly do as someone with the privilege of living in a first world country where I have choices, is to educate myself, and then change myself to best comply with how I wish the world was.
So, I don't like battery cage eggs? I don't buy from McDonald's (for that and other reasons). I don't buy them at the grocery store. I avoid buying them in products whenever
reasonably possible. I do have chickens, but if I did not, I would seek someone that did. Local eggs too expensive? I'd seek out local keepers that offer eggs for less, or even barter. It's taken years to do but I have made lovely friends locally that trade with me. I can't grow all the veggies I need, so I trade eggs for them. They don't have chickens and appreciate the "happy" eggs. Don't have local growers (even on a small scale)? Try farmers markets. They can be more expensive, but even if you go and just talk to a farmer, and connect... you would be surprised at the sense of community.
I was once at a point in my life where I was dumpster-diving for food, because I was so poor. I was nearly homeless (and am thankful that I wasn't actually homeless!). I understand all too well the weight of the decision of "more expensive but caused less suffering, or less expensive and possibly suffered, but I can afford to eat it". No one should be made to feel guilty when finances force your buying hand.
I am just one person. But imagine what would happen if even a tiny percentage of the population took this approach when they were able? How many less battery chickens would be "needed"? The rewards of approaching life this way are many. The rewards of sending a petition off are also rewarding, but in the end it is a battle.