I’m right there with you! Always brought a backup Bass to gigs and needed/used it once due to a battery that was beginning to wear but could have finished the gig. And since I purchased a Genz Benz 10 +/-?? years ago, I bring a backup amp. And never needed it.Never, playing since about 1978.
However, when I change strings, I keep the old set in the case, just in case a string goes.
But nice to have “just in case”!!
Cheers