I don’t think so. A smaller pool does mean smaller odds that someone will take what you are offering and do anything with it, but it’s still possible to affect change, especially if you are asking people to affect things actually within their control.

But, with that said, your impact will likely be stronger if you communicate with the people near you locally instead of online, since you and those (physically) around you are affected by the same localized forces.

The internet is a good place to collaborate on ideas and methodologies; your local community is a good place to try to implement those things.