Canada has experience based on the SARS epidemic as well, as it hit here too. A royal commission was set up, responses were studied, changes brought in to prepare for the next one, and stockpiles of medical equipment built up.For my money it's partly the experience of SARS leaving governments more practiced in the specific measure needed but there's a more fundamental explanation in East Asian governing culture.
Simply put, the Japanese, Taiwanese, Korean and Chinese people expect competence in government and have low tolerance for its lack, which in turn shapes the level of preparation their governments undertake.
There's also the aspect that people in these countries generally take more personal responsibility for the well-being of the group - e.g. wearing facemasks to protect everybody else.
A lot of questions are starting to be raised now about whether the wearing of masks by the general populace would be a good idea however. It's not feasible at the moment, because there simply aren't enough to go around, and health care workers need to have first priority over them. The WHO have said that a major reason they don't recommend universal wearing of masks is because it would cause shortages for health care workers (this is a separate issue from N95 masks).
At first the conversation was "but non-N95 masks won't protect you from COVID-19". The message however has started to get through that it isn't about protecting the wearer, it's about reducing the transmissibility from the wearer to everyone else.
In an environment where fighting the virus is all about reducing the rate at which the virus can transmit from one person to another, this may, if it has a genuine significant effect, be a game changer. On it's own it wouldn't stop the pandemic in its tracks, but if it slows the rate of growth this allows time for more traditional public health containment measures (testing and contact tracing) to do its job of suppressing outbreaks. You don't have to prevent all transmission of the virus, you just have to push the rate of growth below 1 for the pandemic to fizzle out.
We of course don't know that universal (or near universal) mask wearing is effective. That will take study, and it will take building up a very large stockpile of masks. Cost is irrelevant, as the cost of masks for everyone is infinitesimally small compared to the measures we are taking now.
But we sure as hell aren't going to find out if this is in fact an effective measure if we spend our time listening to the conspiracy theorists who are running around in a panic screaming that it's all a plot against us and that we need to kill the yellow hordes.