I don’t think people do this because they want to be polite. The ‘hello’ is basically the start of what is the human equivalent of the TCP three way handshake. - Hello (SYN) > Hi (ACK) - How are you doing ? (SYN, ACK) Basically, they are trying to set up a synchronous channel over what is essentially an asynchronous medium. This is even more annoying than just slowing down the answer, they are demanding your undivide…
Paying proper attention was always core to effective human communication. Will we ever adapt to being async all the time?
If you want to create a venue where attention is obligatory, schedule a meeting. Then we can also have a look at the meeting agenda relative to is duration and our total meeting load, and make reasonable tradeoffs.