Based on this review only 4 counties in the state of Missouri may have had voting systems that were properly certified on Election Day 2020. This is less than 5% of all the counties in the state that had voting systems that were properly certified on Election Day.
This pattern is likely similar in other states. Assuming it is, less than 5% of the voting systems used across the nation were certified according to EAC guidelines and yet all the states certified their 2020 Election results.