Most important, is the nature of Europe - it is densely populated, and all largest countries are separated by mountains or big water.
Because of this natural divide, Europe has not unified culture, non unified business regulations, and much less space to grow.
You could consider, US is 300 millions unified culture, and EU 500 millions, but divided to 3-4 most powerful cultures and tens smaller.
So when in US could be one very large company, in EU will be at least 4 different sub-companies for each large culture.
And unfortunately, Internet is business of largest possible scale, need large unified environment.
Example, how made films in EU in 1960s. Typically, films where made by international companies, and very normal was, when in one scene heroes speak on three languages, and than made dubbing to each country, where film exported.
- Hollywood that time already made direct sound tracks, without dubbing. And this was cheaper an faster.
And many languages is not only such difference, there are lot others, each add some costs.
Second important difference, most interest European countries are very densely populated, and land prices are high, but in least interest is not easy to make big data-center, because uncomfortable regulations.
Mean, not easy to find customers in for example, France, but place dc with their data in for example, Hungary.
So in Europe exists large gap for companies want to grow from small, like google at start, to big cloud, like current cloud companies.
Azure and GCP still bleed billions of $ despite all manner of accounting tricks (google includes Gmail in their cloud revenue!, Microsoft does something similar)
So far as I know AWS is the only profitable large scale cloud service. Probably because of their first mover advantage giving them scale (customers and products offered)
Note the cost of electricity Germany is the most in the world [0] compared with US prices [1].
https://www.electricrate.com/data-center/electricity-prices-... [0]
https://www.electricchoice.com/electricity-prices-by-state/ [1]
"Europe witnessed the birth of 85 new tech companies with a valuation of $1 billion or more in 2021, taking the total unicorns in Europe to 132, and registering a unicorn growth rate more than twice that of the US.
However, it should be noted that this does not mean that more startups became unicorns in Europe than in the US (there were 340 new unicorns in the US last year), but that the US growth rate was 124% from 2020 versus the EU growth rate of 400%, i.e. 17 new ones in 2020 and 85 in 2021. "