The Supreme Court is upholding the rule of law. If Musk refuses to take action on the massive propaganda and disinformation campaigns that are rampant on his platform and lead to a fascist (like a literal fascist who praised the military dictatorship and openly said it's only mistake was not to torture enough) getting elected, banning it shows that the democracy is still defensive and able to protect itself.

We can't let tech monopolies just ignore any democratic rule and do whatever they want.