The latest IRS Statistics of Income Bulletin (Publication 1304 (Rev. 11-2022) (irs.gov)) show that 164.4 million individual income tax returns were filed for 2020, or 4.2% more than in the previous tax year. Only 9.5% of all returns filed claimed itemized deductions; the vast majority used the applicable standard deduction amount.
The 2020 return reflected various COVID-19 related tax changes enacted by the CARES Act of 2020 and the American Rescue Plan Act of 2021, including:
A tax technique for receiving a refund of back taxes by applying a deduction or credit from a current tax year to a prior tax year. For example, a business net operating loss may be carried back for two years.