Believe it or not, but candidates don't have to be set in stone. I'm no fan of "but we couldn't do anything about East Palestine" Buttigieg, but I'd take him over either leading candidate any day. I have an even lower opinion of Newsom, but I'd even pick him. Biden is no longer in a position to be a strong counter to Trump.
Edit: in anticipation of good faith questions, my top pick of all major democrats would be MN Governor Walz. I genuinely believe he is the most competent leader in the entire country at the moment, but he has absolutely no aspirations for presidency.
LOL I just had a discussion with someone in another thread about how Walz would be great, but the person I was talking to said he didn't think Walz had the name recognition.
Without a doubt, he'd be amazing. Unfortunately his lack of recognition outside of the Midwest is also a huge downside. He'd be seen as a nobody coming from the weird lefty state