General consensus seems to be(among what's left of the Swing Voters and Moderates, not a large group) is that Harris won the debate, showed she was professional and a capable speaker, and Trump made a fool of himself in the back half and lied chronically in the middle. Harris won, that was what people hoped for.
However, Harris staggered a bit the first 15 minutes before Trump got knocked off balance, and she didn't really do a great job of explaining policy on her more controversial issues or directly addressing the flip flopping allegations(which could have been a problem, but by that point Trump was ticked off and lashed out emotionally instead of going in for the kill). Trump lost, but both the moderates and the betting markets suggest it's not a Biden June level loss. The market loss was 4 points instead of 5 and it's recovering quicker, there isn't the same mass panic you saw after that on the Republican side, it's more subdued panic.
Trump lost, but not campaign endingly so. Harris won, but she didn't do the best job of explaining her policies which is the number 1 concern of swing voters. But also Trump didn't capitalize on this, Harris knocked him off his game early and got him panicking so he couldn't counter attack on those points when they came up.
I have my doubts Trump is going to go again, Harris knows how to push his buttons and get him off course before any of her more constroversial opinions come up. Trump can't afford another debate loss. Harris probably wants to avoid dealing with Vance directly though, I think he could bite his tongue long enough to go at it more directly. Leave him to Walz, Walz doesn't have that baggage.
Also it'll shore up polling a bit, added to by the Swift thing. Probably a good idea for them as the Honeymoon period(which a lot of people were starting to write off as non-existent or a conservative lie or something to that extent) did seemingly end in the week leading up to the debate. Harris slumped and her lead shrunk.
It's sort of a game of chicken at this point. Harris doesn't have time to fully pace a slow burn campaign or bury policy flips deep enough back in the past to commit to a classical strategy. Trump's been in the campaign longer and COULD sit out and try to let Harris slump. but her higher baseline and long honeymoon made that too risky. Harris won last night, she knocked Trump off his game before he had to chance to sink his teeth into the flipflopping. Does Trump risk a second run and hope he can hold his cool until she exposes herself or dodges a question or does he sit it out again and wait for this polling spike to fade by October? A loss in an October debate could be disasterous as it's right before the election and there's no time for a bump to cool down. A minor Trump win could shore up numbers at the last second. Sitting it out depends on what Harris does, which has been a mixed bag, but it puts the ball fully in her court to go on the offensive.
Harris would absolutely win in a full length campaign season, but there's too little time for that and that creates weak spots. Weak spots Trump can exploit, but due to his own weak spots going for it is risky and last night Harris won that gamble.