I don't think Trump even wants to be president again. He knows he wasn't good at it.
I believe he's running primarily in hopes of shutting down the prosecutions against him and avoiding prison or financial ruin as consequences of his own actions.
I'm afraid he very much does want to be president again.
He wants the power.
He wants to jail his political opponents, journalists and prosecutors.
He wants to make money off of the country, and from foreign countries.
He wants to help Putin.