It completely depends on how well you take care of it. Many keep their Macs 5-7 years or more.Will it last significantly longer than a Windows machine?
If by last, you mean USABLE, and not necessarily being more sturdy...
They both last the same. Neither are readily scalable, and the folks making software will throw us more features we don't use, take up more space on our hard drives, or SSD, then of course increasingly more complex webpages, have you notice how many videos they have now? will surely obsolete ANY laptop you may buy.
Modern electronics are no longer like the olden days where you can expect to keep your Trinitron for 20 years.