Lot of well put points.
Aside: found myself disagreeing with the analogy of the bass and a spoon in cooking! A quality musical instrument can make a difference to our sound eg Stradivarius vs £50 violin; they're not the same thing. A great violinist will sound very good regardless. But he or she will sound better on the Strad played with a top notch bow (which can, by itself, cost more than a high-end electric bass). And you can blind test that any day of the week.
But that's, of course, not a comment on 4 vs 5 vs 6 string basses.