Async communication by txt not only avoids interruptions to what Im currently doing (often difficult programming / analysis tasks) but also. with txt there's not the expectation of immediate answers like there is with voice. With txt I can reference material (code, results, calendar) and or think deeper about a response, consider angles and second order effects and THEN respond. This leads to much deeper conversations and more well thought out execution.

I see a call as rude generally, because what its saying is "Stop what you are doing, give me all of your attention and talk to me about my topic right now, and answer me right now" and 99.99999% of the time, nothing is that urgent