Of course many of us are gratified about rumors that RFK Jr. might drop out from running for president in order to help Donald Trump win the election; we're not proud, as every vote helps. But he's doing this all wrong.
One assumes that Bob would carry a lot of Democrats with him, while one isn't quite sure there's many voters to be picked up if he urged them to vote for Trump.
To help, he needs to stay on his side of the fence and draw disaffected Democrats to him, not Trump, thus bleeding Biden. Nobody's going to vote for Trump over Biden, but they'll vote for RFK Jr. over Biden.
Thus making it easier for Trump to win in a three-way race.