Very few professors are granted tenure, as was the case in the past. It's weakly non-zero: times have changed. There are far more adjunct professors today. Universities are more run like businesses than in decades past.
Adjunct professors are not tenure track, so there is really no expectation that they would get tenure. Though I have seen the numbers that say the number of adjuncts is increasing.
One of them just plays videos of himself in his lectures. He doesn't actually go to them. He is actually around during less than half of his scheduled office hours. He complains to (and at least once has shouted at) the TAs about how students keep asking him questions. He has tenure.