My daughter is using my old 2008 aluminum MacBook daily. I've replaced the battery, swapped out the HDD for an SDD and bumped up the RAM from 2 Gb to 4 Gb. It's running Yosemite and everything is working great. Keeping my fingers crossed we can get another 2-3 years out of this machine.
I had a 2006 MacBook that finally gave up the ghost a few months ago after nine years of daily use.
Finally, I have an iPad 3 that's still going strong and running the latest version of iOS.
I replace my iPhones every couple of years so I can't speak to their longevity.
Although the original spec limited the 2008 alu Macbooks to 4Gb RAM one of the post-release firmware updates upped that limit to 8Gb. Mine’s been running fine with that, at least. Also, it’s on the support schedule for El Capitan.
I had a 2006 MacBook that finally gave up the ghost a few months ago after nine years of daily use.
Finally, I have an iPad 3 that's still going strong and running the latest version of iOS.
I replace my iPhones every couple of years so I can't speak to their longevity.