There's no such thing as a five second interruption. Once my concentration has been broken that is a ~15 minute process to get back into a flow state. This is human psychology. There's nothing wrong with me being distracted by distractions.

Asking "hey you got a minute?" is a waste of everyone's time because either the answer is "yes" and you could have asked your question already or the answer is "no" and you just disrupted someone who was doing productive work and still doesn't know if your actual question is worth answering right now. Just ask your question and I will answer it when I have time. This is why it is better to ask in email, IM or a meeting, depending on the nature of the question.

If I had a coworker who reacted to interruptions the way you describe, I just wouldn't involve them. I'd grab other people and make decisions without them. I'm sure you react to interruptions the way you describe, but I wouldn't treat it as a universal.

Like I said, everything you're writing speaks to you.

I encourage you to review the concept of "flow". You may be missing out on valuable input from capable contributors by excluding them for having a regular human reaction to interruption.

https://en.wikipedia.org/wiki/Flow_(psychology)

How about disabling notifications when you are in flow and checking messages after you done. Effectively same as putting on headphones when in office.

I do disable notifications when I am in flow. That's why I prefer working from home. I have control over that.

In the office respect for the headphone signal is not universal. Also, sometimes I don't want to wear headphones just to signal I am in flow. Nor do I want to have to use them drown out all the other distractions. People are still walking around and doing things, all are potential distractions.