[trnglina]

I can speak a little on Chinese and Japanese. In neither of these countries, English (or sometimes even Latin) literacy is high enough to replace the domestic language. (And anyway, maybe it's just me, but reading romanized Chinese or Japanese is exhausting.)

With China, the market's so big that there's an entire ecosystem of homegrown (or Chinese-modified) software and websites, everything from office suites to web browsers, and I have to imagine those support Chinese input just fine.

With Japanese, generally the same software and sites are used, but Japanese support is also pretty good across common software.

Some niche or open source software struggle with IMEs in general, but in those cases, the solution is just to not use that software.