Fair points, but I feel like they're still coming from utopian thinking, although they are true and valuable thoughts.

Oligarchs are always chipping away at democracy, even if they have the best intentions. And I use "oligarch" very broadly - everyone from corrupt congressmen to corporations (and their shareholders) benefiting from government spending. I'm also not saying capitalism is bad - I'm a capitalist : anarcho capitalist, specifically - or that corporations are bad. But as long as the political framework is democracy, the system will trend towards corruption. That's because of two reasons : people are incentivized to take from other people, and they vote that way ; and as long as its possible to take from other people, oligarchs will use the power of the state to enrich themselves.

What's the limit to their theft? The only limit is when force rises to meet their force. This is usually a cost/benefit calculation, since credible resistance rarely materializes. The more centralized the state, the more theft. If it costs more to send thugs to steal (taxes, levies, prohibitions, licenses) than the state can afford, they won't do it - so in edge cases, freedom can exist, but only because innovation hasn't yet allowed the ravaging democracy to steal more by saving costs. The edge cases all disappear in the long run.