In the UK’s case, feudalism is alive and well. The entire tax system is designed so parasites descended from thugs like the Duke of Westminster or Charles of Battenberg-Saxe-Coburg und Gotha never have to pay property taxes on their extensive land holdings.
That was worse in the 18th and 19th century, and yet people were willing to ground new corporations back then.
I think the answer is something the left won't like - we (Europe) are killing ourselves with bureaucracy, often environmental bureaucracy. A road to hell paved with good intentions.
The documentation to the Lower Thames Crossing, a planned highway tunnel, already exceeds 360 000 pages. This is just crazy.
Since Europe is to the left of the US, whatever the US is doing right (pun intended) is bound to be something the Left won't like.
The US also has plenty of bureaucracy, and what's worse, a lot of it stems from Common Law and capricious courts that interpret it, which is partly why large civil engineering projects like upgrading the NYC subway cost 4x more than the equivalents in Western Europe (minus the UK) or Japan.
I think the biggest factor is the sheer size of the unified US market and its economies of scale, and a second one the fact the US Social Security is limited compared to European retirement systems, and thus people have to save in their pension funds, freeing up a huge amount of capital for investment, while at the same time creating enough competition that they don't have the sense of entitlement that British feudals or continental bankers have, leaving entrepreneurs with crumbs.
Source: I'm from France but I moved to San Francisco to found my two startups, because I'm not a glutton for punishment. Then again I moved to the UK (for family reasons), so I guess I am a masochist after all.
I think the second part of your second point is the critical one. Europe has also a lot of free capital, but if it’s invested it flows to the US. Why? Because returns are outsized. But I wonder why?
Yeah, when you think of it, the US economies of scale are huge.
In the European single market, you still don't have, for example, an affordable parcel service. For a Czech e-shop to send a package to France, as I did a few days ago, is something around 12 eur postage fee. It would be 4 eur within Czechia.
American e-shops can send packages from Florida to Alaska for peanuts, and they don't have to bother with translations into 20 languages.
It is often accomplished enterpreneurs who complain of bureaucracy.
I remember reading a German enterpreneur's complaint that he was unable to build an extra electric connection between his two industrial buildings in Germany in less than a year, due to endless rounds of permiting for that single cable.
He contrasted the situation to Poland, where his application on a similar site was processed in two weeks and it took two more weeks to actually build the connection.
If you think complaints of bureacracy have no merit, maybe you never faced any. It now takes about 10 years to get all permits for a regular block of flats in Prague, Czechia. It used to be 3 years or so back in 2000, and it takes only about 9 months in Denmark.
These are experienced developers, and they are still stuck.
That's because risk-aversion and laziness are the smart things to do. Yes, it would be cool to come up with the next Facebook, but most financial advisors will tell you that the actually best thing you can do is some form of "SP500 and hold 20 years" because from the perspective of an individual, the safe option provides the best expected outcome.
Similarly, why work yourself to the bone for a miniscule chance of success, if you can... just chill instead? I used to be a highly-motivated go-getter, but then I realized, this shit ain't bringing happiness, and I turned into a work-avoider who spends time in the office mostly talking to coworkers and playing games in the toilet. My overall life satisfaction skyrocketed.
Yes, the society at large does need people to do the needful, but this ain't gonna be me.
The us generally would do 95% in the safe s&p500 and the other 5% in high risk things. The exact numbers varry of course but that is a good rule of thumb for good future growth.