If you were Cruz why would you want it? Ted Cruz wants to be president. Being vice-president is not a path to that in the best of circumstances. Being vice-president to someone like Trump who completely sucks the air out of every room he enters would mean eight years of being a total non-entity. Eight years of hewing to Trump's less-than-conservative line and loyally supporting the administration. And that would kill any chances Cruz ever had of being president himself.
In my lifetime, Richard Nixon, Lyndon Johnson, Gerald Ford, and George HW Bush were vice presidents elevated to the presidency.
Hubert Humphrey, Walter Mondale, and Al Gore have been their party’s nominees, even though they lost.
That means that vice presidents have been more than relevant in ensuing elections. I’m one who has long believed that Dick Cheney would have been a far more formidable opponent for Barack Obama than was John McCain.