I kinda skipped thru the book, but it seems aimed at singles or couples who live in a flat. I live in a house, I need a lawnmower, a snowblower, and lots of other stuff.
Duplicates: I have a claw hammer in my workshop, another in the garage. Likewise scissors... I have scissors in the workshop, the garage, the office, the kitchen, and the sewing box. Sure, when I need to open a package in the kitchen I could fetch the office scissors, but... why? It's not like I'm short of space.
Also, I suppose a flat-dweller could manage with one hand saw, or even none, but I have two hand saws, and a hacksaw, in addition to a skill-saw, a jig saw, a mitre saw, and a sabre saw.
Do my saws "spark joy"? Don't be silly, they are tools.