I personally would like to see either a negative income tax or guaranteed basic income program to replace Social Security. However, I acknowledge that the greatest hurdle/downside to these programs is that unlike SSDI, they don't have a veneer of "paying into the system" that SSDI does, and that veneer, no matter how misleading, is a large part of the reason that this particular social welfare program is so difficult to eliminate or modify out of existence.
Absent that, I do agree that an elimination on the income cap would be relatively painless for the economy, but then again I don't believe in the idea of a "job creator" class. I personally would experience a significant increase in taxes under such a program, although I would argue removal of the cap should be accompanied by a permanent reduction in the rate, maybe to the 4.2% we saw for a short time a few years ago. Maybe better yet, a complete removal of the employer portion of the tax while leaving the employee rate the same, which should allow for wage increases, most dramatically at lower salary/hourly levels.