Ahem. The Alps, the fjords, the Netherlands, the Mediterranean coast of Spain, are all very different landscapes.
The population density of the combined regions is probably a red herring, too: nobody sane will cycle from California across Nevada to Salt Lake City, except as a fitness holiday. Even my 1080-km cycle along the Rhine (flat from Hoek van Holland to Switzerland) isn’t something anyone sensible would do to get from A-to-B, and I flew home instead of cycling back to the UK.
Instead, what will matter is the average journey time from where people live to where they want to go, and how much effort it is to get there. Electric bikes will help on both counts.
Yes you have a wide variety of population densities and climates. So does Europe. So does everywhere else in the world.
It's the most boring and lazy argument to make, and it never actually answers anything. Exactly what is so different about LA compared to Paris that it can't have good cheap internet and cyclists must die at 5 times the rate?
I've lived without a car in the US for over a decade. I no longer have a driver's license. I would like to see America become more pedestrian friendly and bicycle friendly.
I don't think you accomplish that by arguing that "Well, you just do everything exactly like the Dutch!" I think that's a lazy, unhelpful and disrespectful answer that actively ignores real and meaningful differences between the literal and figurative landscapes of the two countries.
It's not good communication to say "Just do everything exactly like the Dutch." If you want real solutions in the US, you need to think in a more nuanced way about what pieces of the Dutch experience you can reasonably use in the US, taking into account real differences between the two places.
Ignoring the differences between Europe and America very often comes across as open contempt for Americans and their presumed stupidity and laziness. It's not an effective means to promote actionable ideas.
No one is likely to take advice that they are just wrong and stupid and lazy and should wholesale copy a system that works well elsewhere without bothering to examine differences between the two places and trying to make some alterations that will hopefully result in a better fit.
Based on the comment I replied to, I feel like San Diego, California could try to borrow ideas from the Netherlands without a lot of critique beforehand. But LA has vastly different weather from Paris and a very different landscape and history of development. So, no, you aren't realistically going to replicate Paris in LA.
I will also note that they have been rioting in Paris. Paris is not some perfect paradise that has figured everything out and never has any problems.
Claims of European superiority are frequently overblown.
But I don't think that means we can't borrow any lessons at all from them. The biggest lesson we can borrow from the Dutch seems to be that they set out to intentionally make their cities more pedestrian friendly and bicycle friendly starting in the 1970s when people became extremely fed up with children dying due to being hit by cars.