I often find myself wondering, how can I help tip the scales back the other way a little bit?
Some would probably chime in with "free software" initiatives like GPL, distributed protocols, and the like. Those sound nice on paper, but with a few exceptions I haven't seen much evidence that they actually translate to a real liberating effect. This is partly (not completely) due to the fact that you usually have to be technically savvy to even take advantage of them.
What are some technology projects that would put some agency back in the hands of normal people?
> put some agency back in the hands of normal people
You mean providing technology tools to people who aren't technical to give them more agency and thus promote liberation of society from the grip of powerful groups.
Alternatives to captured communication / publication / payment platforms enable this, at least temporarily, until they get shut down or get captured too.
So, maybe work on more unstoppable uncorruptable communication / publication / payment platforms.
However, beware that availability of these tools won't necessarily achieve the liberation effect you might seek. For that, people have to believe in that kind of liberation, they have to care enough to alter their behaviour. One of the big problem of our times is that too many people choose to live in blissful submission and resignation to the power, instead of processing available information and making rational determined decisions. This is not a purely technology problem, which is perhaps why even many technologist people are in that group. But technology may still help to combat this, by connecting them to people that think differently.
It's a hard problem, and fundamental to it is that it's a people problem, not a tech one.