Trump and Musk, man, they're too scared to actually go at it. That's why they're just talking smack about each other. You know, when a dog barks, it’s not gonna bite. The real threat is the one that growls and goes for your throat.
It's because they are both in a way powerful and influential and they have their own images to protect. They probably have lies that they want to keep secret so they just shut their mouth otherwise why would they be scared to really go at it as you said?
Elon Musk tried to but soon retreated back. I mean you don't target a president of a country and expect no retaliation or consequences even if these things are private.