I don't think I've had a tube with more than five patches, but some of them are going strong after 30 years. Main reason for taking them out of service is a leak at the valve stem.
I find it curious that some folks don't want to spend the time putting a patch on, when it's likely that they spend more time acquiring a new tube. I usually buy a bunch at a time, but it is difficult to source the right size tube, at a reasonable cost, with the right length stem (I prefer shorter stems).