Many of the people I do have online conversations with speak English as their first language. I kinda get by but you native speakers really underestimate how hard it is to express oneself in a foreign language. Concepts work differently, metaphors don't really translate, references you have used for decades don't make sense.
Like in German I am actually somewhat eloquent and texts I write don't look like a person with a head injury wrote them.
@tante two weeks ago I had suddenly won the task to translate everything we do in Krav Maga into English for a new participant. It worked out and we had fun together but it was a horror without knowing the domain specific vocabulary so well^^