I would advise anyone at or near retirement age to go to this ssa page and download the detailed retirement calculator anypia.com.
https://www.ssa.gov/oact/anypia/index.html
Through using this calculator, I have found that there is an "MFB" (Maximum Family Benefit) amount that cannot be exceeded when collecting SS. Additionally, after calculating my benefit for each year of my age from 66 to 70, and adding my wife's spousal benefit, I reach the MFB at age 69. Even though the MFB increases with any cost of living increase, your SS benefits increase by the same percentage. Therefore, once your benefits meet or exceed the MFB, you cannot collect any additional benefits (unless something reduces your benefit before you file, like the death of your spouse).
In my case, if I waited until 70 to file for SS, my wife and I would lose about $60,000 in benefits vs filing at 69.
It definately pays to understand all of the rules of SS, and to calculate your potential benefits yourself. Do not rely on a SS employee alone to give you every option. For instance, for the many times we have been to the SS office asking many questions, we did not know until recently (from an on-line artice) that my wife could claim her full SS benefit while I take her spousal benefit, and then later switch to claiming my full benefit (much greater than hers), while she claims her spousal benefit (1/2 of my full benefit). Her spousal benefit does not increase, however, after I turn 66 (my full retirement age).
You need to do the research yourself and find your optimal SS strategy. Do not rely solely on your local SS office to do it for you.