Privacy

That's one way to do it, I guess. For most people it's simpler: develop a second writing style and only use it online when sharing sensitive information — such as when whistleblowing or sharing pirate content. That writing style should:

1. Prioritise brevity. The less you say, the harder it is to tie your online personae.
2. Stick to the standard spelling of the language you're using. Typically there's only one standard way to write something, but multiple non-standard ways.
3. Avoid as much as reasonably possible words and grammar that reveal your location, social class, education level, age, or any neurodivergence you might have.
4. Only use three types of punctuation marks: comma, period, interrogation.
5. Keep text structure simple.

Small note regarding people who speak 2+ languages: keep in mind each language you know interferes on your usage of the other languages, often in predictable ways. Even your native one. And this can be used to narrow down a bunch of profiles to who you are.