Many New Cars Have No Spare Tires

Its not about knowing how to change a tire. It never was safe to be outside a vehicle on the shoulder of the road for any reason. Ask state troopers.
About 1980, bumpers started disappearing. The jack point on majority of passenger vehicles moved from the ends of the vehicle to the sides of the vehicle. So a left side tire will put you out there in harms way, just like those state troopers.
Hell, even in a situation as safety minded as NASCAR, pit crew members are hit. That's 30 vehicles? at 11 seconds? average. Versus how many vehicles and how long on the public roads? The driver is in the safest place.
Modern technology has provided low air pressure warnings, and run flat tires, and most importantly communications.
Factor in the millions of spare tires that were never touched. They went flat or dry rotted away. That compares to a insurance policy that turned out to be worthless when needed. Remember the Uneasy Rider? "limped on down the shoulder on the rim". A rim could cost you a nut today.
Bottom line, Not every change is for the worse.