Overall, 70% of U.S. adult citizens who were eligible to participate in all three elections between 2018 and 2022 voted in at least one of them, with about half that share (37%) voting in all three.
I'm not sure how intense your off year elections are, but one of mine had only a single uncontested race, so I'm not sure I'd jump to considering missing some of the offyears "abysmal".
Based on the numbers I'm looking at, the people who didn't vote were the ones that were likely Republican voters. The people that stayed home were likely Republicans who did not vote for Trump. I'm all for political engagement, but I'm not sure how invested I am in making sure Trump gets all the votes he told people not to cast.