It depends. I mean, continued use of a mechanical feature will at some point not feel as stiff or as new as it once did. Still, if you feel as if something's not right about it, take it to the nearest Apple Store and have them check it out for you.
I think if I get the chance I will take it in, because for some reason it's not responding like it should, I was setting up my friends new 6+, and I could definitely feel the difference
Take it in to an Apple store if you feel that there is something wrong with it. In my past experience, I have never had an iPhone's home button that becomes weary over time.