Its the quality of the steel mostly. The poorer razor makers got a bad rep and went under so the ones that are still around now are, by and large, the good ones. There are exceptions of course!

It'll also depend on how well looked after it was by the previous owner(s). If they took good care of it, kept it dry and didnt cane it on the hones that'll make a real difference in how well it performs today and how easy it is to hone.

JMHO of course, but a good product well looked after will last a very long time. A cheap product or bad ownership will shorten the life hugely.