I totally agree with the last few posters that eliminating the cap should be considered... when I was working it was always a mystery to me and I would have been fine with it if it helps to save SS.
The next question is if the cap is eliminated then do you allow the addiitonal taxes paid by those impacted to factor into their benefit calculation or not.
My view would be yes... you need to allow those paying those additional SS taxes to gain some benefit... to not allow an increase in benefits would be an additional nudge of SS towards being just another welfare program (more than it already is given the bend points in the benefit calculation)... and IMO the popular support that the program has will wane if it becomes just another welfare program.
According to this source (perhaps a bit dated but still relevant in an order of magnitude way), subjecting higher wages to SS tax would solve:
A. No maximum on earnings subject to tax, no Increase in benefits.. 88%
B. No maximum on earnings subject to tax, increase in benefits... 71%
C. Increase but not eliminate maximum on earnings subject to tax, increase in benefits... 29%
I would chose B.
Try your hand at Social Security reform | American Academy of Actuaries