In a similar vein, I have a couple coworkers who regularly DM me on Slack to ask “Hey, can I ask you a question?”

First off, you already have.

Second, you know the answer is yes. Why ask?

Thirdly, you’ve wasted my time and made this potentially asynchronous interaction synchronous. After typing “sure” and hitting enter I am basically entirely guaranteed to sit and wait for your second question because you have already interrupted my thought process and whatever I was doing.