For me it's very easy to tell because I've been living under a Communist regime and now in a "capitalist" (or "democratic" to use a more PC term) system so I know the difference extremely well. Many books have been written about this but essentially it boils down to the freedom of speech and the amount of punishment you can receive for criticism or being disobedient to those in power. People in the West have no idea what it means to be constantly afraid for oneself and one's family, to be totally at the mercy of a soulless system with no justice at all and no recourse, to learn not to trust anyone, even one's neighbors and family members and so on.
Getting back to your question: of course we are all brainwashed (or "culturally conditioned"), this way or another. But there is an abyss of difference between living in one of these regimes that criminalize everything that is not official vs living in a Western country with all its particularities and inconveniences.
Of course there's a cost to this. Liberal democracy is intensely annoying and always expands to embrace whatever kind of diversity is too much diversity.
That's how it can be a target for fascist uprisings: people want to pretend they're open to all things and have all freedoms as long as there are no consequences. In reality, there's one cost to restriction and another cost to multiculturalism and diversity.
If you look at it in a-life terms you see the autocracies as plateaus. Stuff gets locked down, and there's no progress. But progress hurts. Liberal democracies and their tolerance of diversity are about coping with all the unaligned interests of starkly different people, knowing that combining those people is what gets you startling progress. It can almost be reduced to simple mechanical terms, like recombination in a genetic soup.
It's always possible to crush inconvenient genes and have everyone the same (to a point, and if you're determined enough). And then, you don't have those genes anymore, and your future's narrowed.
Freedom of thought, freedom to travel not only for some vacation, even just a neighboring state firmly within your bloc. Not being executed on the border. Watching what you say, constantly.
You have no idea how much that means to you until you properly lose it. Then suddenly there are very few things in life worth more.
Getting back to your question: of course we are all brainwashed (or "culturally conditioned"), this way or another. But there is an abyss of difference between living in one of these regimes that criminalize everything that is not official vs living in a Western country with all its particularities and inconveniences.