I wrote, “But if that were the only remedy, then a rogue president plus 34 partisan hacks in the Senate could do anything.”
You answered, “Isn’t that what we have today?”
That’s what we have IF the Supreme Court agrees that a president can’t be prosecuted for anything unless there’s been an impeachment and a conviction. On that view, Biden can leave office on January 20 and never face any criminal liability for any of the charges you went on to list.
My view: Biden can’t be prosecuted for bad decisions on border policy, because, no matter how bad the decisions were, they’re part of his official duties, so he’s immune. But if it could be shown that he took bribes or the like, then he could be prosecuted. That will be the result if (but only if!) the Supreme Court rejects the argument you make in the OP.