Good advice I've learned here is to start taking SS in a down market anytime between 62 and 70. That way you are selling less of your investments at a low. Basically you are betting that the additional investments you are able to keep in the market will rebound at a better rate than you'll get in SS increases by deferring.
Some people think they can beat SS increases in any market. Certainly possible, but not without risk.
The possibility of future SS cuts certainly makes a case for taking SS early.
Longevity insurance is a strong case for taking SS late if you have other funds to get you there. You can still spend the same way as you would if you took it at 62, it'll just be coming out of your other investments, knowing that you'll be getting a bigger SS check at 70.
Your personal life expectancy outlook certainly plays a factor.
Some people just don't have the other funds available to wait to take SS.
There are married/family situations that may apply. Since I'm single I don't keep up with those.
There are other factors I've either forgotten, or don't feel have much merit.
Most likely, it won't make all that much difference when you take it.
Personally, with 6 years to go, longevity insurance is my goal, but the possibility of cuts after I become eligible and timing a down market means that waiting until 70 isn't necessarily the right choice for that.
EDITED TO ADD:
Keeping income low to qualify for ACA subsidies is a good case for deferring until at least 65. Leaving room to do a tIRA->Roth conversion under the 15% cap is another reason to defer.