Individuals are unlikely to be able to do something about the centralization problem except vote for politicians that want to implement countermeasures. I don’t know of any politicians (with a chance to win anything) that have that on their agenda.

There is a crucial step between having an opinion and voting. It's conversations within society. That's what makes democracy and facilitates change. If you only take your opiniom, isolated from everybody else, and vote from that, there isn't much democracy going on and your chance for change is slim. It's when there is broad conversations happening when movements have an impact.

And that step is here on HN. That's why it's very relevant to observe that that HN crowd is increasingly happy to support a non-free internet. Be it walled gardens, geofencing, etc.

That’s called antitrust, and is absolutely a cause you can vote for. Some of the Biden administration’s biggest achievements were in antitrust, and the head of the FTC for Biden has joined Mamdani’s transition team.