That is your view, but the judges did not rule that way or say that.
Because the cases they are ruling on are not about 2020.
Their votes were all legal and counted.
The question in the title of the thread is about what Biden (or the Democratic party more generally) did.
These rulings make clear that officials acted illegally, so the answer to the title question is yes.
You are right that the typical voter didn't knowingly do anything wrong, and were mislead by Democrat officials.
You are also right that there isn't a way to fix or undo the damage the official's actions caused.
But that doesn't change the fact that Joe Biden was likely elected because of the illegal actions of his supporters.