Hilariously, nobody can explain why it would be in Democrat interests to save McCarthy. He could have negotiated with them, but he refused to do so.
He was already reneging on the agreement he made with Biden. He unilaterally started pointless impeachment hearings on Biden, instead.
McCarthy reportedly told his own caucus that if he remained Speaker, he'd go against the Democrats even more.
All the Republicans have to do is to elect a new Speaker. Every single Congress has been able to elect a Speaker so far.
Oh and by the way, it seems that Trump cannot be elected Speaker due to some rules of the House that Republicans put in place about electing someone with felony indictments.