> the claim that in future these are all automatically going to die off is a post-dated cheque
It's not, though. We've literally seen this development happen over and over again and it's a logical consequence of the system as is the increasing monopolization via acquisitions and buyouts.
We're not in purely laissez-faire capitalist system, certainly not globally, but trying to paint present day Berlin as an example of a social market economy in the "Rhine capitalism"[0] spirit shows a complete unfamiliarity with the practical evolution of the German economic system and welfare state during the later part of the 20th century and the early 2000s, which saw a massive shift towards free market capitalism, especially under (ironically) the SPD-led Schröder government.
> Villages in the UK stockbrocker belt have little litter, despite being composed of wealthy incomers.
This isn't a counter-example to what I said, this is an example of what I said. Income isn't the determining factor, ownership (and legacy) is. Additionally, even if they don't expect to live there forever because they're comfortable relocating to follow the money, they're surrounded by potential business partners. This again isn't about their level of income but it creates a social mechanism that incentivizes displaying "good behavior".
> Another example is cartels.
An example for something avoided under capitalism? Certainly not. This is like saying Western countries don't have corruption because money is used to exert influence by signing entirely legal backroom deals (campaign financing in the US, promises of zero-effort board positions and highly paid "speaker" engagements in Germany) instead of literally handing wads of cash to police officers.
And this isn't even to cede that cartels can't happen under capitalism, let alone under laissez-faire capitalism: they're not prohibited by the market but by regulations (i.e. laws), and even then there are always loopholes to enable corporations to engage in functionally identical behavior as long as they follow a sufficient number of layers of indirection (or are comfortable to use a pile of NDAs to hide actual illegal behavior). A recent US example widely discussed on HN was the "no poaching" agreements between large industry players to put a cap on the salaries of highly desired employees.
[0]: The term is "Rhine capitalism" not "Rhineland capitalism", btw, and it's a gross oversimplification to use it to refer to the post-WW2 German model, the economy of France in the 1990s and the economy of Germany after the Agenda 2010 reforms as part of the EU-wide Lisbon agenda -- which was one of contributing factors to the EU debt crisis, drastically raised the poverty rate in Germany, drastically cut the income tax rate and wreaked havoc in the welfare system. It was a stretch when Albert popularized the term in the 1990s (after the German reunification) and it's frankly ridiculous to still use it today.