I have both.The only reason I would own two identical pistols would be to have a backup for a carry gun.
I do not, though, I usually instead have a second gun that's close enough to replace a carry gun reasonably well if one goes down.
Like a slightly different size/caliber Glock (19/26/23/27 etc) or 1911 (commander, CCO, compact)
So there's at least two different approaches, and some will pursue both approaches at the same time.
1. Get multiples of the exact same gun. I have this
2. Get slighty different versions of essentially the same gun. I do this, too