Having a selection of multiple amps seems more desirable to me than multiple basses at this point.
That can be true if you have a versatile bass. Right now, I essentially gig with one P and one DB simply because they suit everything I'm playing.
I currently have these amps:
1. Walter Woods MI200-8 head, Bergantino HT-112 cabinet. For BG only or BG/DB doubling gigs. Second HT-112 is added when more volume is needed, like outdoors. Seen in my avatar.
2. Acoustic Image Coda combo. For DB only gigs. AI Ten2-EX cab is added when more volume is needed.
3. A.M.P. BH260 head, HT-112. For hosting at blues jams. It has much simpler controls than the WW, just one volume, just one channel so even my mother could figure out how to dial it in. It also has a ballsier sound than the WW.
4. A.M.P. BH420 head, EAW VB-115 cab (EVM loaded). Used for loud BG gigs where I want the old school sound. This used to be my main gig rig, then the blues jam rig but now doesn't get used often.
5. Roland Street Cube EX combo. This is a battery powered amp used strictly for street busking. I run a BG into one channel, vocal mike into the other.
6. L.R. Baggs Paracoustic DI preamp. Used only for amp-free DB gigs where I can plug into the PA.