Even if they did, creating a Chinese IME is a really difficult problem space. Since typing is generally done phonetically in mainland/HK/taiwan and the real words being typed are ideographic, there's a lot of inference to translate in between.
Considering how quickly the language moves to keep up with internet culture and new newsworthy names, new parlances, new memes, an IME has to do the equivalent of staying up to date with the equivalent of urbandictionary for users to be able to invoke the latest "lit" colloquialism. This is a full-time job on its own.
Considering how quickly the language moves to keep up with internet culture and new newsworthy names, new parlances, new memes, an IME has to do the equivalent of staying up to date with the equivalent of urbandictionary for users to be able to invoke the latest "lit" colloquialism. This is a full-time job on its own.