I have spontaneous conversation and ideation daily at my remote job. In slack. Both with teammates in DMs and team channels, and in more general channels.

I have never had trouble asking people questions. And I get asked them all the time. In fact, that the questions and answers are written and async is superior. When I was in the office, people would frequently take conversations to Slack (or say "could you Slack me what you just told me?")

Personally too, I find written communication to be superior. I will do quick video calls with people but that's rare (and usually to the taste of the other person).

We also have excellent training backboned by mentorship.