Although in my experience all the traffic from East Asia and Oceania (Australia, Japan, Korea, Hong Kong, Singapore, etc) to Europe goes through the US. So network-wise, the US is more central.

Agreed the network is much denser in Europe than the USA. This is obvious if you've really tried looking for network infrastructure services. The USA is just where a lot more high-level services are, like social media, due to the peculiarities of capitalism. There's no shortage of infrastructure there either, of course.

Data caps are apparently illegal here. This is good for the quality of infrastructure.

And if you have customers somewhere else you want to be in that place, or close to it network-wise.

I did some research about this a while back: https://utdemir.com/posts/choosing-cloud-regions.html#:~:tex...

You are right, the best region that optimises median latency against all internet users over the world is `us-west-3`, which is Paris - I believe. Likely because it has much better latency towards Asia where the majority of internet users are.

I also investigated which two regions to choose for a multi-region setup, which ends up being London and Japan.