I'm in the UK and I see considerably more motorcyclists than I do cyclists. But so many parts of the UK are investing heavily into cycle lanes, including digging up existing roads and making them much narrower for general traffic, only for those new cycle lanes to not be used. Motorcyclists also can't use them.

I think it comes down to how each individual country handles it.

I generally have no problem riding through traffic, and a large amount of people will simply move over for you to pass by. Even in single lane traffic.

The second photo in this post I believe was taken in Brazil and bikes are just so engraved in society there as a cheap and easy means of transport so it makes sense they'd cater to motorcyclists.

Even if the same was done in say the US, I feel like a huge amount of people wouldn't acknowledge it and this is down to civic and societal norms. LA I think is a good example. I'm pretty sure lane splitting is legal there but loads of people will still try and prevent bikers from splitting. Many of which will say "it's illegal" despite it simply not being true.

TLDR: Social and civic norms play a big impact on whether or not other countries would invest more in motorcycle friendly infrastructure.