Yes, cables could do the trick too of course, have worked perfectly fine my entire driving life .......but with these you remove the must have for vehicle #2.
I tend to do solo riding, so waiting or looking for that other vehicle could be an issue or require some wait time.
The other dilemma is sled batteries tend to not be as easily accessible as they could be, so that means taking partially apart two sleds for that jump start.
They also provide a USB port to power other things if you're in a pinch.
When on sale, the amount spent of them is pretty marginal, IMO.
They are small, likely find a padded pouch for it and store it in the glove box of my sled, making it easy to keep it charge as needed between rides vs. stuffed away.
I have never relied on electric start to date, my new sled will be the first, so I think pro's out way the con's.