The question is a good one, especially from a workingman's tools perspective.
I used to play covers, but never did anything like session work. I don't buy guitars as "tools". Your comment that "if you don't work, you don't eat", does not apply to guitars in my life. My work is statistical analysis and manufacturing problem solving. Guitars are for enjoyment. Creating music is enjoyable, and hunting for one that can bring something new to my tonal pallet is also valuable to me. It isn't needed to put food on the table, it brings peace and sanity after doing what does put food on the table.
There are other "hobbies" that offer relief to others in a similar way
; some costing far more money
.
High end watches,
High performance or luxury automobiles,
Photography,
Hunting and firearms shooting,
The list goes far longer.
I enjoy playing guitar and I enjoy finding the next one. It's not about tools. It's about making life meaningful. To be clear, the most meaningful part of my life isn't guitars and music. The most fulfilling part of my life is investing in my wife and my children's lives. Paying for college and walking life's highway with them is far more costly and far more rewarding than my hobbies. Giving up Saturdays helping someone move or paying for a hotel room so a family that has broken down on the road can get their car fixed is far more rewarding than searching for the next blue guitar (for Sergio).
There's more to life than putting food on the table. If one has disposable income, it soothes the soul to use a little of it in pursuit of nice things.