South Korea has a dense population and just came out of a centrally planned economy wherein they had to create a modern network and just rolled out fiber almost everywhere. That's a very special case. At the 'start' of such central/social reforms, leaps of progress can often be made no doubt, the issue is what happens in the long run.
I've managed some local networks (remotely) in this region for some high traffic sites: quite a handful of Asian countries have high bandwidth dense fiber inside the country, but it tends to go to crap as soon you exit the country/bottleneck heavily.
For example, Japan has 1G being common, SK has 1G being common, Taiwan has 500-1G common. They all bottleneck quite a bit exiting the country (except for TW, but to some destination countries only); and as a side effect, many "local" websites are extremely popular as opposed to being subject to other countries' laws and media.
SK has side effect of also having an extensive DNS and RST/hijacking-based national "great firewall" censorship system that is officially deployed for pornography and pro-NK articles, but has also been used for anti-LGBT rights websites and other purposes in the past, in addition to threats of forcing foreign companies to comply with heavy surveillance requirements like requiring national ID to comment on a blog post. Honestly, SK is not a great role model for internet or censorship. On top of that, while your "home" connectivity is fine, content providers trying to set up even CDN/caching nodes in SK are subject to serious annoyances, like the KRNIC/KINX crap where they really dislike it if your ASN isn't allocated by KRNIC - you're literally on the internet exchange already but all Korean ASs will not talk to you or give you time of day because you're not one of them, and are not present on the route server, and you're forced to route traffic that originates and terminates in Seoul through the US or Hurricane Electric or some other insane route.