In the battleground states, turnout actually was higher than 2020 except in North Carolina (down 1%) and Arizona (down 3%). In Michigan and Wisconsin turnout was up 1.4% and 1.3% respectively!
In non-battleground states, turnout for the most part was lower than 2020. But not by much. New Jersey was the biggest decline at 8%. But most states were only slightly down.
Since 2020 is a weird benchmark- it was a record turnout election due to pandemic rule changes- 2016 is probably a better comparison.
Nationally turnout was up since 2016. Most states were also above 2016 turnout. Only a couple were slightly below 2016 turnout.