Small scale co-op bicycle manufacture and repair is eminently feasible. Especially if it's a simple single speed.

The problem with farming is that the world is arguably over-populated, so you need mass scale high tech farming to feed all those people, especially with global soil degradation approaching catastrophic levels and climate change reducing yields.

Small scale farms will never be enough. Also, it would likely actually be more polluting, because you'd end up tilling (which contributes significantly to emissions) or fertilising less productive soil, and need more passes, when you have places where the soil needs relatively little tilling and fertilising. It makes sense to use the most productive soil, in the most efficient way possible, which means large scale and super high tech.

It's really not for the amateurs. Co-op orchards, jam and juice manufacture? Sure. But it'll never be enough. That's best left to the experts.