Both of your points have some merit, but I still don't see any dispute of the breakeven math.
From a purely financial standpoint, it's never optimal to delay SS to 70. The 9 year breakeven assumes a TVM of 0. Even at just inflation, the breakeven starts stretching to 12 years. If you factor in what you should expect your fungible money not taken out of retirement accounts due to SS payments to return, you're talking 16+ years.
It never makes sense to delay.
For the record, I plan to take SS at age 62, based on current rules. However, my reasoning is that taxes play a bigger role. Let's just look at age 62-70. I'm going to end up going into age 62 with far, far more money in my traditional IRA than my Roth IRA because I won't be retiring until something like age 50 and the overwhelming majority of my retirement funds are in my current 401k as well as a rollover traditional IRA from a previous 401k plan. My understanding of the tax code is that you can generally take Social Security tax-free as long as your income is below a certain threshold.
If I wait until age 70, then my SS income is way higher and with RMDs it is going to cost me way more in taxes. However at age 62, I'm getting a lower SS payment, making it easier to take SS as well as have plenty of room to convert traditional to Roth while that SS income remains entirely tax-free. Again, that's assuming no changes to current tax code, which are certainly possible. Still, the current tax code basically seems to encourage people with large 401k/T-IRAs to take SS earlier, and keep converting as much T-IRA to Roth as practical in those years from 62-70 before you have to start taking RMDs from the T-IRA.
The point I was trying to make was that if somebody who's been working poor all their lives is still healthy enough to keep working beyond age 65 anyway, they are probably healthy enough to go several more years, and maybe all the way to 70. This working poor worker likely has no other retirement savings, so they don't have to worry about tax implications or RMDs or any of that. If they're healthy enough to work right up to 70, they are probably one of those people who may live to 95, and that higher SS payment would help out for sure. It's going to be different choices for different workers and their unique situations.