It’s “citizen-funded” not because you ignore the fact that “that’s money taken from citizens” but precisely because it’s money “taken” from citizens and given directly back to them.
And re “ban[ing] other spending”: Again, your words, not mine. As I’ve explained (Republic, Lost v2 (2015)), at a minimum we need to change the dependencies for funding congressional campaigns — shifting to citizens generally rather than an unrepresentative few. Beyond that, I support reversing SpeechNow, which wouldn’t affect “spending” but would give Congress the power to limit contributions to independent political action committees. That wouldn’t “ban other spending”; it would just avoid the corrupting dynamic we now see with superPACs. My expectation is that those two changes will be enough to end the corrupting dependence Congress now has.