Control the media, you control the information that a significant part of Europeans get. Elections aren't won by 50%, you only need to convince 4 or 5% of the population that the far right is great.
There is a reason Musk paid so much for Twitter. If this stuff had no effect he wouldn't have bought it.
By exposing people to a flood of misinformation and politically radicalizing content designed to maximize engagement via emotion (usually anger).
Remember when Elon Musk alleged that he was going to find a trillion dollars (a year) in waste fraud and abuse with DOGE? Did he ever issue a correction on that statement after catastrophically failing to do so? Do you think that kind of messaging might damage the trust in our institutions?
To be 'fair', finding fraud never was the real purpose of DOGE, just some fake argument that enough citizen would find plausible.