She's doing as bad as trump on every single issue and has shown to be worse on some (deportations). On top of that people like you gave a shit when he was in office.
People are willing to forgive all of that as long as she isn't committing a genocide. And then you have the gall to talk about 100% agreement? Pull your head out of your ass. It's not just "this one little issue" (and even if it was, it's a FUCKING GENOCIDE) it's the fact she does nothing on all of them.

What is President Trump II / President Vance going to do about climate change? Women’s health? Concentration camps for immigrants? Future elections?

The same as Kamala.
Kamala will be worse though, because if you let her get away with genocide, then the gates are open. There's nothing left. Showing the ruling elite that you don't even fight against that, shows them they can do whatever they want. Doing that will be so much worse than having a slightly ruder and more obviously decrepit version of Joe Biden in office.
You will stand one day and ask who will speak up for you, and no one will for they will all be gone already.

Also elections are literally a popularity vote, dumbass