Ideally, I'd love for Dems to just start taking credit for everything MAGA brags about. Since apparently the Republicans aren't in charge.
The record of contemporary recognition of their lies is important. Every day there are people who, knowingly or not, are teetering on the edge of leaving the MAGA cult, and these call-outs catch some of them.
MAGA's base isn't an entirely static crowd over time. Some people leave, and new people are indoctrinated. Efforts like this are important to trying to reduce the number of people vulnerable to becoming MAGA, to reduce the number of people actually becoming MAGA, and to increase the number who leave MAGA after finally seeing whatever was enough for them.
MAGA has shown repeatedly that large-scale efforts to crack their base apart aren't effective, which mostly leaves us with trying to keep new people from joining and trying to shake a few people off the edges wherever we can.