I agree that carrying a spare makes less sense if its in your home country, or adjoining countries on main roads. Especially if you have to buy a wheel , and dont have a wheel well.
Sure I could call out a breakdown service , and might need to do so anyway if the car is somewhere hazardous. But they (or I ) can fit my spare and I'm on my way. Able to arrange ,at my convenience , tyre repair or replacement with a brand of my choosing, , or even sourcing a new wheel of the correct type.
Its probably 15 years since I last needed to fit a spare . But without it I would have needed to call out a breakdown service It was out of hours so unless a 24 hour mobile tyre fitter could attend PDQ its likely we would have needed at least one night in a hotel for two couples.
I,m not advocating it for everybody , but for some of my Journeys I am happy to sacrifice some boot space to avoid this situation, however unlikely . Especially as I often travel in remote and mountainous parts of europe, with potholes. It helps that I have two sets of wheels and can use one as a spare. Imagine how I would feel, stranded, miles from anywhere, knowing I have suitable spare sitting at home in the garage.

I thought some readers might be interested to see how it looks.