I think that it depends on several fcators as to what you prepare for , travelling out in the outback , I carried two spare wheels on my Landrover , and a tubeless tyre plug kit . In my RV due to size and being tubeless I just carry a new tyre casing , as have tools , and easy job to change tyre on tubeless truck rim . Plus the cost of a "emergency" supply tyre would be astronomic
. The goop stuff is in majority of cases a waste of time , or unusable(tyre u/s) Better with a tubeless plug kit , and 12v compressor . So in the end it comes down to personal degree of risk , and inconvenience you are willing to put up with if the situation arises . I dont think there is any dumb or wrong choice , unless you go to the outback with 4 bald tyres and no spare , or water