I suppose they are fine if you have a small place. We have 80 acres on the home-place and 160 acres leased. Most of our electric fences cross/fence large pastures so they can be grazed more efficiently. We have creeks, trees, brush, lots of deer and even have feral hogs to deal with. We have frequent wind storms and infrequent tornados and big storms. We also have frequent power outages. So, they are constant maintenance problems.
I can see that small farms with paddocks away from trees and wild game would be easy compared to fences here. In western Oklahoma and Texas it is not unusual for ranchers to have 1200 acres or bigger winter wheat pastures in one field with nothing but electric fences to keep the cattle in. Again, they have to be driven and checked daily because deer or drunk drivers are bad to take them out.