What do you mean these days? Computers used to obsolete within months in the 90s as ever-faster CPUs kept coming out.
No longer true, with the death of Moore's Law. Computers from 2010 are still quite usable (I have several, servers & laptop) since speed increases over the last decade are incremental at best.
I've been buying computers since the 80s and now is the golden age of longevity for equipment.