One thing that I think might be missing is the scale/population of a government's jurisdiction and perhaps the considerations of moving to more local government when it comes to the context of voting.
I'm thinking in terms of Nassim Nicholas Taleb's Skin in the Game[0] where broader forms of government (eg, US Federal Govt) are smaller (ie, more "Libertarian") by only focusing on protecting our constitutional rights while more local forms of government can become increasingly more socially democratic, but impact fewer people overall. This allows for controversial ideas to be experimented in smaller scales while allowing for competition and escape from undesired policies. A policy that proves itself useful can spread due to the actual proof of it working. Voting at the highest form of government should be a rare occasion where we can maximize the incentive to vote.
Perhaps proportional voting enhances citizens’ autonomy, by giving them greater control over those issues in which they have greater stakes