What happens is from 2022, IRS will use new distribution table to account for the fact that people are living longer. The new formula reflects life expectancies that are about one to two years longer than in the current life expectancy tables, which reduces the size of RMDs.
For example, under the current formula, a 72-year old with $300K in an IRA will be required to withdraw $11,719, under the new formula, that amount will be $10,948, a 7% difference.