In what way was the President of the Weimar Republic representing an institution more like the Supreme Court?
Hindenburg put Hitler up as a choice for chancellor and then appointed him chancellor.
That’s a little different than what you’re suggesting.
Throughout the history of the Weimar Republic there are many examples of presidents using their emergency powers in big ways.
I think saying that president is a figurehead position with no real power is pretty indefensible. We have well documented examples of presidents wielding lots of power and the specific one we’re talking about famously used his political power to put Hitler next in line.
It’s doubly damning that you’ve brought this up as a defense of voting for Biden when one extremely shallow but nonetheless true reading of the events after Hindenburgs election is “don’t elect senile politicians to office if you want to defeat fascism!”