Once the capitalists get enough control of the government they rig everything for themselves. In a capitalist system money is paramount and they have the most of it, so their opinion is regarded higher than everyone else's. Once capitalists rig the system for themselves, the only way to get ahead is just pure luck or connections. Sine not everyone can be connected, luck is all that's left for most people, so it becomes a huge part of economic activity along with whoring and warring. See Also: OnlyFans, and the Department of War.

I think the main cause (that's actually quite anti-capitalist) is that banks and people at power have the ability to create money out of nothing, to lend the money into existence, while devaluing everyone else.

It was very interesting to me where I finally understood how banks (and the overall system) create money. As a bank you start with 0 money, you lend 100 to some person that you "deposit" into their account at your bank. So now on your books you have 100 in liabilities (the money that the person has in your account) and 100 in assets (the money the person owes you). So accounting is balanced. You did not need money to start with, as a bank you just "lend it into existence".

When Bill Gates was the richest guy in the world, he still had to battle the authorities for ten years to import his sports car from Europe.

I'd hardly call that controlling the government.

It’s interesting take for sure. However it appears that in real life nowadays most millionaires are self made. I was surprised when I found out about it too. Seems to contradict your thesis.