Not slagging on you but someone will inevitably say that you should search the topic because this has been discussed to death. Doesn't bother me, just a guess.
In all my years of playing I've needed one twice and those were both in the early days where I didn't have the $$ to have a backup bass. Now I always take two, always. Too many variables, it's an easy thing to do so why not. Better to always have one and never need it than to need it and not have it.
And I usually play both of mine at a gig so there's that too.![]()
need? No.
Is it nice to have? Yes.
For years it was only one, then I got a beater bass on the cheap. But still, I didn’t always bring it as a backup. Why? Because 95% of the time, there was no room to place it on stage. I was usually only allowed the most microscopic of footprints.