Mike Johnson is running the House the same way McCarthy did; he’s using a coalition of moderates to get essential legislation through the system, while giving the extremists the opportunity to do whatever they want on other issues. But McCarthy was defenestrated, while Johnson clearly won’t be, as he has support from the Democrats. What accounts for the difference?
Three things: experience; personality; and circumstances. The Democrats have learned that most of the alternatives are worse; Johnson doesn’t lie to them, as McCarthy did; and there is little benefit to either side (other than the extremists) to having another round of chaos with the election looming in about six months. Even Trump clearly thinks so.