The answer to 'how long does rewiring last' is that a properly installed home rewiring project can last for 30-50 years or more. Electrical wiring is designed to have a long lifespan, but the actual longevity can vary depending on the quality of the materials used, how the wiring was installed, and the home's environment and usage over time.
Older homes may have outdated wiring that is no longer up to modern safety standards. Rewiring an older home can significantly improve its electrical safety and reliability, as well as increase its overall value. A professional electrical contractor can evaluate your home's wiring and recommend whether a full rewiring is needed or if targeted upgrades would be sufficient.