That is a very valid concern, and what primarily drove me to optimize on Dynaplug and tire inflator kit for the cars that don't have factory provided and packaged full size spares (and accompanying supplies to put it to proper use). I have one car left in the garage with a full sized spare, and all my cars have sets of winter wheels and tires. But I don't carry those on my trips for the reasons stated above.
I did just that the last time we drove to Florida - got a puncture in driver-side rear tire on I-95 outside of Miami.
Pulled over on the shoulder, had my wife drive slowly forward until I saw the offending screw in the thread, pulled it out, plugged with two DynaPlugs, re-inflated, and was back on the road in under 15 minutes start to finish. Kept an eye on pressure readings - all good all the way home (1+K miles).
Granted, those were exciting 15 minutes on the shoulder, but for me, that sure beats sitting and waiting for a two truck hours on end. In either 100 degree heat or 10 degree cold.
BTW, my wife could have done the same on her own as well!
A full size spare is the best, but very few car companies package those inside modern cars theses days.
A donut is least useful and borderline worthless to me, since donuts come with speed and total range limitations (usually under 60mph for fewer than 300 miles, then done).
That is a super rare corner case that I don't worry about anymore.
The most common tire puncture scenario is you drive over a nail with the front tire, kick it up, and (occasionally) it bounces just right to penetrate the rear tire. There is no feasible scenario for it to bounce into the sidewall.
To damage the sidewall, you really need to hit something (a curb) hard enough, or run over a huge pile of rebar or metal planks. Not impossible, but not likely either.
The one time I needed more than a Dynaplug was when I ran over a huge pothole on a rural road, at night, not far from home. Both passenger side wheels were bent badly (boo on Tesla soft 20" wheels), to the point of tires getting fully deflated. I had to leave the car, get a ride home, then come back to swap out the bent wheels for winter wheels and tires. Then had the wheels repaired and ready for the next season.
HTH,
a