I think you over estimate the power of money on people’s thoughts and opinions.
The original claim was that our brains are broken because we respond to propaganda. I don’t have the inclination to address the opposite claim as well.
Sure it works...to a degree. But if people don't like you or your ideas, all the money in the world won't change that.
Trump was absolutely loathed, such that getting him out by any means far outweighed Biden's personal popularity for most people. Biden's slumping poll numbers indicate that he has little support in his own right.
AOC is unusually charismatic and youthful, in contrast to a somewhat dull middle-aged opponent that she defeated. But there were 3 other factors at play in that race: Crowley, the incumbent, had won his seat 20 years before in an open race following a retirement, the political equivalent of easy mode; the demographics of the district had changed during his tenure; and the DSA are decent organizers who took advantage of the general low turnout in NY Congressional primaries.
There are certainly lots of ways to overcome the influence of money on politics, but understating its influence is as naive as throwing in the towel when outfunded. Again, if things like advertising didn't work candidates wouldn't spend so much on it; and if money didn't matter political operators wouldn't put effort into pushing the legal envelope to allow more into a race.
Consider a recent case, in which Ted Cruz successfully sued the FEC to get rid of limits on the use of post-election fundraising to retire personal campaign debt (ie where a candidate loans money to their own campaign, which is not subject to campaign contribution limits). Cruz 'overpaid' by exactly $100, incurred a fine, and litigated the case. Previously, the limit of $250k in post-election fundraising put a ceiling on the amount of money a candidate would typically be willing lend to their own campaign; now you can raise any amount from your supporters after the election.
https://www.fec.gov/updates/supreme-court-finds-limit-on-can...
Going back to your first post, you could argue that bloomberg threw vast amounts of money into the race because he wasn't worried about being paid back. But that's kind of the point; Bloomberg spent $1 billion and people laughed, because there was wide public awareness that he's worth $82 billion so losing one of his 82 giga-bucks was not a big deal. He had big name recognition because of his news business, but not big personality recognition outside of NY, and his extreme willingness to self-fund ended up looking even more crass than Trump. This was the political equivalent of an army provisioned with a million swords but only 5000 swordsmen.
Corporations have tens of billions to spend on marketing. To put things in perspective: what do regular people have in terms of a propaganda budget in order to target corporations?
The very fact that corporations have these kinds of budgets to just point at regular people—and regular people have no recourse other than “don’t be stupid”—betrays the fact that ours are democracies in name only.
If a nation had a population of millions and a handful of billionaires who just bought off the politicians then the real fundamental problem would be the massive wealth disparity, not the fact that the billionaires could de jure buy off politicians (they could have done that de facto if there was no such explicit law).