Let’s take these two separately. As to money: the evidence shows money isn’t buying results. Wall Street and Silicon Valley strongly supported Clinton in 2016. She outspent Donald Trump by 70%: https://www.theguardian.com/us-news/2016/dec/09/trump-and-cl... ($340m to $581m). But Clinton lost.
Within the Republican Party, billionaires billionaires wanted someone other than Trump: https://fortune.com/2024/02/26/ken-griffin-koch-brothers-rep.... But he’s going to win the primary.
More generally, the donor money in US politics supports globalization/free trade, and mass immigration (for cheap labor). The money is losing that battle not just in the US, but in Europe too.
The problem in U.S. politics right now is that Internet-based donor networks have eliminated the ability of large donors (and institutions) to control the candidates.
As to gerrymandering, what makes you think it has any real effect? Do you have a numerical estimatr in your head of what the party split would look like in Congress if there was no gerrymandering?