When I was young I bought a brand new Contax 139 with a 50mm Carl Zeiss Planar because I wanted "the sharpest lenses". Soon after I joined St. Louis Camera Club. They would project our slides and
critique them. There were photographers with Contax RTSll's, Nikon F3's and Canon F's. There were also photographers with Pentax K1000's, Minolta XGM's, Olympus OM1's, etc.. etc.
When I looked up upon those images, to save my life I couldn't tell you which photos were taken with which cameras.
I'm not saying that all 35mm camera lenses are completely equal but if you really want a difference in sharpness then you need to move up a format.
My daughter has an Olympus OM1 and her 50mm is plenty sharp. It sounds like you just got a hold of a bad example.