People are uninformed. The reality is that they vote incumbents when they feel good and for change when they feel bad. And, in the end, winning the voter base means being the best at propaganda and swaying how people are feeling. Unfortunately, even if you want to do the right thing, you still have to win people over with propaganda. Pushing for good policy that’s too complicated for the average person with the attention span of a small rodent to follow doesn’t work. Its why Trump always gets crushed in the debates and still wins elections. People literally think they’re voting for the economy which is a net positive for everyone and that Trump doesn’t mean the hateful stuff he says. That’s how good their propaganda game is.
There are non capitalistic economic systems that are also don’t require state ownership and are non authoritarian. Literally just incentivizing worker owned coops is an example of how you can drastically shift the economic system without changing the political system. Markets =/= capitalism. The ability to hoard capital and thus power through private ownership is capitalism. I’m not saying that what i described is the perfect system, it’s just an example of something possible outside of your argument.