I've been using plugs for 40 years without any failures.
The last tire I plugged was on my Mazda a few weeks ago. I got a low-pressure warning on I-10 and pulled off into a parking lot. I found the leak, pulled out the nail, put in the plug, used my 12v compressor to refill the tire, and resumed my trip.
I was glad I had the plug, because my "spare" is a tiny donut that is good only for very limited miles and speed.
My plug repair is for unlimited mileage and speed.