This isn’t to say that I always respond immediately to something whenever I see it, text, email, message, or otherwise. But I eventually get back. And if I know at the outset that a simple direct answer will satisfy the inquiry or close down the discussion, that’s what I do. A simple acknowledgment of receipt is courtesy.
Courtesy is sadly I believe something of a dead social expectation. If I know once I’ve seen something I don’t have time in the moment to respond, but I will later, I am even going to send you a message stating so much. Again, it’s a matter of courtesy.