Blackjack insurance bets

I hear never take insurance over and over like its some automatic rule, and most of the time I pass on it, but I dont buy that its always a dead bet no matter what. If the dealer is showing an ace and the shoe has been running heavy, I can see why some players take it and arent just lighting money on fire. I had a couple spots this week where it looked right and skipped it anyway because of the standard advice, that gets old when people say it like theres no exception at all