50 psi is too much even if you have passenger. The disadvantage include,
1). Less tyre contact area with riad as tyre is extra inflated. That also means tyre will wear out in centre faster.
2). You will feel every rock, bad road texture, and tinniest bumps and undulation of road. Which is not comfortable.
3). It also results in all the load of road on springs and bushings because the tyre is not absorbing tiny high frequency crests and troughs of road.
4) This is the most important as it is the reason of many accidents because at more than 40 psi the tyre is over inflated that means tyre is in curved shape that means less contant patch with road that means less grip. So, when you apply brake the tyre skids.
Try 25 to 30 psi in front and 30 to 35 psi in back with respect to riding alone or with passenger respectively.
After that try a little brake experiment with updated tyre pressure you will feel the difference.