No, people did not wear masks "all the time" nor did even "most" people wear masks. Go to any image search. Find images before February. (Search Hardly a mask in sight. They are common enough no one finds them strange but they weren't remotely the norm either.
By "all the time", I mean take any given adult in Tokyo and there's a good chance they have experience wearing a mask for a couple days every year.
In Japan it's not only the immunocompromised or healthcare workers who have ever donned a mask: it's nearly everybody.
You'd be hard-pressed to ride the metro and not see a handful of mask-wearers on any given Tuesday in recent years.
Whereas in countries like the United States you'd rarely see masks outside of a serious medical setting, and you wouldn't be able to buy masks for a dollar at literally every corner shop within 100 meters of your home.
There are many others, but this is one of the most important.