VPs are not supposed to be “effective”, they are supposed to deter coups. The current VP is excellent at detering coups. Nobody, on any side, wants to turn the Presidency over to her. Even the Grim Reaper himself winces at the very thought of collecting the over ripe FJB.
Having an ineffective VP waiting in the wings won’t deter a coup. Now I’m not saying Rand Paul is incompetent like our current VP - on the contrary. But that doesn’t mean he would be an effective President. One can be ineffective for reasons other than stupidity, and the Uniparty would be happy to replace a President Trump with a President Rand Paul if they could.
Rand has few friends in Congress and is a poor leader. He likes to go it alone, which is fine if your goal is to be a gadfly. But a President is not a king. He has to work with others to get things accomplished. Why would anyone believe Rand Paul would be effective at taming the Republican Establishment and creating a working, MAGA-centered coalition? The Uniparty has nothing to fear from a President Rand Paul.