I think you'll find that the president who led America through WWII couldn't climb a flight of stairs on his own. Whether or not your assertion about Biden is true, it doesn't seem to matter one way or the other when it comes to leading a nation.
I mean given this person's American history seems to be pieced together from Prager University Youtube clips and OANN I wouldn't be surprised if he didn't know FDR was in a wheelchair.
Their comment sounds like it was generated by a right-wing AI.