Thanks for replying in good faith, that's not usual in this day and age.
In the US, the economic left is a minority wing of the Democratic party. Neoliberals are the majority and have been for the entire Sixth Party System. The "New Democrats" of Bill Clinton -- 30% tax hike on top workers, 30% cut on capital gains tax, gutting of social programs that makes DOGE look like a dog toy, NAFTA, and hey, Epstein connection -- tend to vote with us more often than neoconservatives so we caucus with them but to our eyes they have more in common with Republican neocons than they do with the New Deal Democrats of the Fifth Party System, the FDR democrats who ended the Great Depression, ended elder poverty, electrified rural America, regulated the banks, taxed the rich, and won World War II.
I'm editorializing, of course, but don't come at us with "modern Democrats do a lot of things that look upward-redistributive." We know. They know too, that's why they called themselves "New" Democrats, they were explicitly sidelining the economic left. Obama was a little better, he even did a teeny tiny tax-the-rich with NIIT, but he didn't land the public-option, he didn't end Bush's wars, and he bailed out the banks. When Biden went in front of congress and proposed to tax capital gains like ordinary income, like the states do, it wasn't just Republicans laughing at him it was most Democrats (he probably promised Bernie to float the idea in exchange for support, and Bernie wanted those laughs on the record). The Democrats are a liberal party, not a lib-left or left party, and that penduluum is only beginning to slowly start its swing back. Which isn't to say that leftists are perfect (lord almighty we've got problems), but we've got substantially more focus on "the only war is the class war." Agree or disagree, that's what defines "left," and in the present day most Democrats aren't.
As for policy intent, I started where you are and after reading about the Roosevelts and Reagans of the world came fully around to the FDR perspective: if a policy predictably transfers enormous sums of money, don't accept incompetence as the explanation. But this is an adverse inference and needs examples, so let's list some.
Example 1: IP law. As a science-minded programmer I naturally have opinions on the problems of present day IP law, how the self-funding aspect of the USPTO gives them incentive to over-grant patents, that the bar for challenging trivial patents is too high so the optimal strategy is "lay minefields" not "do research," that bundling favors companies with strategic portfolios and lawyers on payroll, that all these little things add up to a system that helps the big guy at the expense of the little guy. I thought it was idiosyncratic, that the system just sort of evolved that way and a bunch of neutral-intent details turned out to have positive returns-to-capital. Nope. Ronald Reagan. The Reagan-Era IP law "reforms" were effectively identical to my check-list of everything wrong with the patent system. It turns out that every complaint of mine was well known last century and litigated last century -- the "Nine No-Nos" made me literally laugh out loud -- and the fact that Reagan's "reforms" all came in a single package and undid exactly that progress made it pretty clear to me that the crew which did this knew exactly what they were doing. Their checklist was as precise as mine, they were just punching in the opposite direction.
It's even more stark with anti-trust, I don't need to say "they" I can say "Robert Bork." Reagan and Bork brought back the Consumer Welfare standard, where mergers are allowed if a company can scribble a plan with crayons on butcher paper for how their monopoly will actually reduce prices, honest (crossed fingers behind back)! I saw many school acquaintances make many such scribbles and create lots of shareholder value at the expense of consumers. They absolutely knew what they were doing and joked about it in private. The idea that markets don't need competition because (incorrect claim about Standard Oil monopoly reducing prices by 70%) dates back to the Robber Baron era, it was litigated and defeated by Louis Brandeis in the Progressive era, and Reagan and Bork absolutely 100% understood what they were doing bringing it back. The wave of corporate consolidation it ushered in over the last 40 years was the entire point.
There are more examples. The ACA (Obamacare) is the one that bumped me out of the Republican party by convincing me that Republicans weren't legislating in good faith, back in the day. It's even more complicated than the above, though, and that's the problem: politics is adversarial, you must account for the possibility that a scoundrel is trying to force the draw, and it's soooo easy to force the draw by drowning with details. If someone takes 1000 steps to the right and 3 to the left, they can still give you 3 bullet points about how they're totally a leftist. The only defense is perspective.
That's hard to acquire because in general you need to know not just which levers were pulled but how much they mattered, what were the possible motives, what did people know, and which levers could have been pulled. Sometimes it's easy though. When we let Trump print $4T in an election year and he decides to spend $2T inflating the housing market, $1T inflating Wall St, $400B on checks (a 10-for-me-1-for-you ratio) and then, after much begging, graciously concedes to another $400B for a 5-for-me-1-for-you ratio, that breakdown tells you something. When the media spends 100% of its time talking about the 10%/20% that was actually checks, that tells you something. When Elon Musk whines about paying $500M/yr taxes while stacking $200B in wealth for a tax rate of 0.25%, that tells you something. When congress laughs at the idea of taxing capital gains like ordinary income (even Robber Baron lawyers weren't that "extreme"), that tells you something. On occasion, the priorities are laid very bare, and it is important to pay attention on those occasions.
One last thing: the Double Insulation incentives (private funding of campaigns, private ownership of media, rich people systematically in charge of both) exist and are strong. The idea that policy only coincidentally produces outcomes consistent with these incentives beggars belief, first on account of the failure of those incentives to consistently affect the politicians, and subsequently on account of those politicians to consistently fumble legislative intent in the same direction. You need enormous and ongoing feats of mental gymnastics to sustain these explanations, whereas I just need to say "they went where the money was." Because of course they did. Why would they do anything else when they have an infinite supply of counterparty credulity to work with?