We replace when our contract is up. Right now that is every 2 years. If my daughter wants to replace sooner, she has to pay for the new phone. They aren't cheap either.
My husband is pretty handy around the house and I'm learning. He was at work one day and one of my fuses blew in the house, yes I still have a fuse box and not a circuit breaker. I had to figure out which fuse it was and replace it all by myself. It was the first time I ever did that. I also cleaned the dryer lint out of the dryer exhaust thing that goes to the outside. I was doing fine until I had to reconnect the thing to the back of the dryer and to the wall. I couldn't get the clamp nuts to tighten so my hubby had to step in and help me. I also put down a floor in my bathroom and painted my living room.
There are certain things around the house that I'm willing to take on. However, when it comes to electricity, if there's major wiring, I leave it to the professionals.
If I do not need to replace, I will not replace. People tend to get into fads about having the newest and best, what is wrong with holding on to something when its not really bad to start with?