the explanation I got a long time ago is that when something gets so bad that nothing you can do will change it is the time you sit back, crack a beer, and admit “no worries”
Also I feel like you are sometimes expected to give an immediate response but you haven’t had proper time to process the situation. So you just say “no worries”
That's not a feeling, I've been told on several separate projects to literally respond to client's messages as quickly as possible, even if it's just to say "we're looking into the thing you asked about, will let you know as soon as we know something". I guess it's important to not let the people with the cash feel ignored