IME they are just another version of CO2 pumps – with the same limitations – a fixed, small number of puffs. My chum had a puncture a couple of weeks ago and using electric, ran out before succesful inflation. He borrowed a mini pump.
I used to use CO2 until I punctured, in winter, solo, in the middle of nowhere. One of those when you can’t get it up (ahem). I got very cold, used my spare tube, both bulbs and still had a squishy tyre. Luckily I limped to a bike shop a few miles away and fixed/replenished then finished my ride.
Since then, each of my bikes has a mini pump and I don’t use electric or CO2.