With a used bike, it all comes down the the condition, and a 5 year old bike could be great or terrible.
If the bike has seen light use, or seen heavier use but been well maintained, the condition could be quite good. My FS bike is quite a few years old (2012 frame, 2013 fork, 2011 wheels), seen very heavy, hard use, but is in fantastic mechanical condition (though quite scratched up) because I maintain it very well.
Other people trash everything in a third of that time.