I slack and email co-workers who are within spitting distance of me. More often than not they are busy and I don't want to interrupt their flow with something that does not require immediate attention. So I'll shoot a Slack or email their way and let them get to it when they get to it.
You are a saint. I have a near retirement age coworker in the same office who mutters a lot while working and from time to time will just start talking loudly to people across the room. It's one of the main reasons why I got a noise-canceling headset.
That's a nice sentiment, however a lot of people have notifications turned on in both their email client and in Slack, so you end up interrupting them anyway.
While true, there's a significant difference: It's very easy to ignore a notification - the same can't be said about a verbal/face to face interruption.
