I suspect its long past the day when a marginal change in consumption will actually affect the world, even a little. The production of meat (and phones) does not change at all for small adjustments in demand - they are far too large an industry with far too large a lead time to respond to much at all.

In fact, using homebrew solutions or alternative sources actually increases my environmental footprint. Now I'm not only wasting the goods that were created in preparation for me (phone, meat etc), I'm consuming more goods from an alternative source that is small and can more readily adjust for demand, which it does, by providing for me. Which has a further non-zero environmental impact.

So in the short turn (year over year) its actually best to consume only the mainstream sources of goods since their marginal cost is about zero. Whether that seems tragic or efficient is up to the reader.

The market is not insensitive to consumer demand. Your choices don't make a significant impact, but the aggregate choices of all consumers is hugely significant. If we buy less meat and lobby for a reduction in agricultural subsidies, the inevitable result is a reduction in meat production, either through a direct response from producers or through the bankruptcy of less efficient producers.

How's that going for us so far? Its a hard sell, convincing people to change their behavior now (pointlessly; in fact to the detriment of the ecology short-term) for some theoretical good later.

The Ford F-150 is the biggest selling vehicle in the US. Ford haven't even tried to sell it in Europe, because there's no demand. They do sell the Ka, a model even smaller than the Fiesta that isn't available in the US.

Ten years ago, the market for grass-fed beef and organic vegetables was negligible. Consumer demand induced the agricultural industry to start shifting towards production techniques with a lower environmental impact.

Consumer demand matters.

You changing your diet will not have that big of an impact, you're right. Just like your vote won't sway an election. In aggregate, these things matter. In the U.S., over 9% [1] of the population follows a vegetarian/vegan diet. That absolutely has an impact on how much beef/chicken/pork is produced.

[1] https://en.wikipedia.org/wiki/Vegetarianism_by_country#Unite...

Not in the short term - again, the lead time of beef is years. And so on.

Lead time for climate change has been years too. Unfortunately almost nobody cared.