I don't want to diminish what a big win this is for American democracy, but a ruling the other way would have been so completely at odds with the entire structure of American law and government and so inconsistent with the entirety of American legal history (in other words, so insanely and clearly wrong) that it would've made the Dobbs decision look like serious, reasoned judicial practice by comparison. It's not so much a make up call as it is simply calling a fastball that was as dead center in the strike zone as possible a strike.
This is how Roberts gives the left "wins" and it's how he's trying to restore the court's legitimacy in the eyes of the public. He's not suddenly good. But he does care about he court's reputation and its perceived legitimacy. He prefers to carry out his legal sabotage in a more methodical and pragmatic way, to maintain a pretext that it's all about the law, so that the changes he makes endure without serious public objection.