My mom still uses my 2006 Mac Mini Core Duo running Windows 7 when she has students over when she tutors.
Her main computer is a 2007 era Sony Viao Core Duo with 2GB of RAM running Windows 7 and Office.
I'm using a 2008 Core 2 Duo 2.66Ghz Core 2 Duo with 4Gb of RAM as a Plex Server.
I just replaced a Pentium Dusl Core laptop with 4GB of RAM circa 2009 with a newer laptop. I still use it occasionally. It's my only computer with a DVD writer.
It helps that my main use of a computer involves work and my main laptop is work provided.
And the market is saturated exactly because the consumerist need to continuously renew the mobile phone is gone, beyond a few percent that always need to show they own the latest gizmos.