That’s because that is NOT considered “provisional income”.
So you could take $100M out of a Roth IRA in a single year and STILL collect social security tax-free.
The provisional income limits are fairly low so to achieve a tax-free retirement including your social security, you typically have to start repositioning your money before you start collecting social security.
That’s why it often makes sense to delay social security if you are trying to collect it tax-free.
That will give you some additional time to move money into other environments that are not classified as “provisional income” in retirement