I read (or heard on the radio) some financial advisor say that if you begin taking your SSI money at age 62 and invest it all in a mutual fund until you turn 70, then in the long run you'll have more money than if you wait till you're 70 to claim your SSI benefits.
Bingo! My wife is retired and I'm quasi-retired, neither of us are 62 yet. We invested well IMHO into retirement accounts with half of them in Roth accounts (growing tax free). I'll probably quit working when my wife turns 62 and she'll collect SS, then I'll collect it when I turn 62. The idea is that collecting SS sooner equals not having to withdraw as much from our Roth IRAs at that time.
Eventually, the cost of living will increase (inflation) more than the SS check grows and we'll start withdrawing from our Roth IRAs too. But they'll be higher because we gave them more years to keep growing (tax free) before we started pulling from them.