Note that Mike could have got his answer minutes sooner, and needn't have kept Alex waiting. In fact, Alex could have started helping right away!
People who do this are generally trying to be polite by not jumping right into the request, like one would in person or on the phone - and that's great! But chat is different. For most people, typing is much slower than talking. So despite best intentions, you're actually just making the other person wait for you to type your question, which is lost productivity (and kinda annoying).
The same goes for:
Just ask the question! 😫
If you feel it's a bit brusque to simply ping and ask the question, you can still preface your message with as many pleasantries as you see fit.
For example:
It may seem trivial, but asking your question before getting that initial reply also allows for asynchronous communication. If the other party is away, and you leave before they come back, they can still answer your question, instead of just staring at a "ping" and wondering what you needed.
When done right - everyone's happy! 🎉