Automation Digitalization Globalization Capital intensive companies instead of labour intensive ones.
All these things allow for scalability and therefore support a "highlander principle" where very few players can control most of the wealth.
It's not technology at all. Technology doesn't confer the monopoly powers which have led financial giants to be so dominant. Technology can be copied, reproduced and replicated.
The reason is much more mundane. The financial sector has been given dumptrucks full of cash and special privileges in the form of valuable guarantees. They're an adjunct of the government in all but name.
So yes regardless of how tight or lax the regulation is same trend is seen everywhere and the only thing they have in common is the use of technology.
Ignoring that is simply lying to ourselves.
That technology drives changes and also drives capital accumulation increase is something we see for more than 100 years. But in the time between the first and second world war (and short after) we also saw a limiting trend that limited capital power. But since the Reagan / Thatcher areas and somehow now accelerated threw the fall of the so called communist block, dominance of capital over labor power and also over social achievements (look in the sweat-shop countries and look in western countries, that drop social standards to be more "competitive") is rising globally in a rate never seen before.
Never did we have that many possibilities to speculate or to invest, in things that are more and more artificial. One of the reasons of the finance disaster of 2008 where artificial "financial products" that where derived of derivations of real things (housing loans) -- so the investors could not know, what they where investing in. But the possibilities to speculate are growing and growing. Now I read here, that there are people speculating on lawsuits ...
There are so many ways to earn money -- without ever taking up a tool or move a muscle. Just by letting the the computers do the job. But in the end, somebody will have to farm the crops that are used to bake the bread you buy from the speculated money -- or somebody will loose the land, where you build your bungalow on.
It just seems that "capital" has taken over everything: Morals, social standards, individual believes, even religion.
So what you saw was globalization briefly held back and technology innovation going into the war. When that stopped technology started to be used for civilian innovation again and globalization started increasing again now with the help of the computer and later internet.
The villain isn't capital or capitalism they are just pawns in the larger game where technology is the primary factor to look for.
As I mentioned somewhere else. Technology is seen as an externality in economic theory. It's the dark horse that everyone is talking about the wrong way IMO.
I have a slightly different view. The US had some very good presidents. Franklin D. Roosevelt was one of them. He did some serious reforms in the US and countered some of the capitalistic outgrowths. As much I understood, he really did fight for a more human society.
In my view, that was one of the main brakes against capital aggregation. An other of course where the two world wars. These factors where important for the rapid growth of social systems and wealth in many western nations.
The reversal came later with presidents like Reagan in the US and Thatcher in the UK.
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In my opinion, yes, technology can bring capital aggregation and thus become a problem for democracy itself -- but good and brave statesmen can counter this trend. I see the few decades after the 2nd WW, which brought wealth to many people (not only the few), as example that technology needs not to be a money accumulating force.
Human decisions are also important -- but where to take brave politicians, when there are none? The problem is, that we are all already corrupted by money and easy living (and brainwashed by the tv).