...such as this one.
It was because they were more effective at ballot harvesting. They put drop boxes in Protestant churches, and had church elders help parishioners fill out the ballots, and then take them in person to ensure they were counted.
Here is some more on the strategy, but alas it is a podcast: https://www.audible.com/pd/Ep-1269-THIS-Is-The-Ballot-Harvesting-Strategy-That-Will-CRUSH-The-Dems-in-2024-Podcast/B0BMN8G4R6
Podcaster oversells the tactic, as in places where ballot harvesting is illegal but still done by the Democrats, there is no effective answer yet that I am aware of for the GOP to respond.
Remember that redistricting occurred between 2020 and 2022. That likely plays some part in many seats flipping.
They were still +4 or +5 Dem districts. In short, the better cheaters win.