Nikon manual focus lenses are very robust with many are still going strong after 40+ years. My oldest lens is a 28/2 AI that is at least 30 years old and it is still smooth as silk. I have a slew of MF Nikkors because I know that they will probably not wear out in my lifetime if I just do the occasional CLA treatment on them. I've bought rough user lenses that have heavy cosmetic damage, stiff aperture rings, etc., but the glass is still great and they produce great images. The modern plasticky lenses would not fare so well, especially the consumer grade stuff.
Originally Posted by Thingy