Short term this is disappointing, but long term I think it is for the best. Being unanimous makes it less likely a state will ignore the rulling, and had they ruled against Trump, then we would have seen decades of retaliation from red states removing all democrats for any reason.
The root of the problem remains that nearly half our voting citizens support electing a violent and hateful criminal.
Elon still can't run, because the states still have authority over enforcing the qualifications for president enumerated in Article II Section 1. The Supreme Court ruling only covers Section 3 of the Fourteenth Amendment for federal office holders or people running for federal office. I honestly like this ruling. The conservative justices ruled this way because they wanted to keep Trump on the ballot, but if they are going to do that no matter what, I'll take the win. edit: added clarification