See page 25 of 2021 IRS Pub 590-B for the correct information: https://www.irs.gov/pub/irs-prior/p590b--2021.pdf
That IRS web page is simply wrong because it has not been updated to reflect the law change provided in the Taxpayer Certainty and Disaster Tax Relief Act of 2020 which made 7.5% permanent. It was previously scheduled to revert to 10% in 2021.
