I live in Sweden and can tell you that, "My bandwidth is full-duplex 100 Mbit, which is a bit slow by Swedish standards," isn't really true. Sure, fiber is common in certain areas but full-duplex 100 mbit? Not many have it because very few need it. It's far more common to go with your cable provider's offer of 10/1 or 25/1 mbit because that's fast enough.
I'd be surprised of most people chose cable over fiber - everyone I know choses to download TV after it airs in America instead of paying comhem 500 kr/mo for shows that are 2 years out of date.
But true, while 100/100 Mbit is commonly an option in big cities (when I looked for an apartment in Malmö a few years ago, all the ones I looked at had 100M-1Gbit), I'm sure most people go for the cheaper 100/10 option, since most people aren't uploading anything. One friend has 250/50, which seems like a good compromise.
Yeah, same here in Slovenia - even though FTTH providers have 100/100 available, people usually opt for cheaper 100/10 or 10/10 options because of pricing (100/100 is 100€/mo, 100/10 is 27€/mo, 10/10 is 22€/mo, which is a noticable difference).
Also I noticed there are very rare use cases when I'm able to actually get over ~30Mbit or so downstream, usually the servers I'm downloading from aren't capable of delivering data so fast.
Can everyone in the neighborhood (assuming they all use same provider) max out their connections at the same time? AKA Does the upstream provider have that much bandwidth?
Definitely not, I mean, even web hosts and colocation centers will oversell their bandwidth.
That said, I ran a internet radio station + free image host node on my residential connection and was pushing a few TB/mo up and never got any complaints. And BitTorrent is obviously quite popular in Sweden so I'm sure there's a bunch of seeding going on.
