The real path is only with Kamala. And saying "anyone else" feels really disingenuous as you know she is the only option with so little time remaining.
Nominating Kamala means:
1. The Democratic Party is being proactive, instead of depending on reactive fantasies that Trump will bury himself somehow. A sign to all Americans that the party is truly concerned for the future of this country. Trump and all of his bootlickers don't think the Dem party has the balls to do it. It will rattle hem.
2. The age issue completely gets flipped. American voters will have their blinders removed and have the chance to see the age issues and mental decline and overall ridiculousness of Trump due to the stark contrast with Kamala.
3. Reinvigorates party enthusiasm and fundraising. She can seamlessly run on the Biden administration platform.
4. Easier to convince and remind voters of the threats to women's rights when Kamala is the face of the campaign
5. Kamala getting nominated is the only chance to get Trump into another debate, and she has the ability to perform well. If Trump refused to debate her, it will hurt him with some voters. Frankly, I think he'd have to debate her. The optics would be terrible for him otherwise. And as we've all seen, optics REALLY matters to voters.
EDIT: All of the above is also taking into consideration that if Biden dropped out, he would say shit like "This is a decision that I made with my family" blah blah blah. He wasn't forced out, that he realizes this is the best path to victory and best thing for our country.