It depends on the sewing machine. Some of the older machines from the turn of the last century are still going strong. I have a couple of Singers from the early 50s that have a beautiful stitch and work great. These machines have metal gears and of course no electronics. They were built to last. I purchased my Viking about 15 years ago. It gets a lot of use and I’ve had no problems with it. However, I don’t expect it to last as long as my vintage machines. Most modern machines have plastic gears and other parts and I’m sure the electronics have a limited lifespan. Also, a lot depends on how you care for your machine and regular servicing. You also need to consider whether it’s a low end or high end machine.