For decades I've been saying that all text input should go through OS-level IMEs (input method editors). For more complex scripts, the need is obvious, but even writing in English, we can get great benefits from a system that expands abbreviations, replaces easy-to-type sequences with proper Unicode chars, runs little scripts and inserts the output, gives you quick dictionary/thesaurus lookups, gives you emmet-style powers, etc., whenever you're writing and in any app.

Of course, everyone's preferences will be different, so you'll get default IMEs with default configs, but with the idea that you can reconfigure or replace them entirely with systems that work the way you want to work everywhere you input text. There have been utilities that do this sort of things for decades, but they've always been treated as clever hacks rather than standard text input.

In other words, instead of powerful text input methods being the exception, they would be the rule, and apps that didn't use them would be the exception.