In your first paragraph you say Trump lies his ass off. How do you square that with Biden's lies? Do you chalk them up to dementia, or are his lies ok while Trunps are not? Can you post the picture or a link to the website of the politician who you hold as the gold standard and has not lied?
And no matter what you think of the election, there were irregularities and laws that were not followed. We live in America where Freedom of Speech is protected, and he has every right to question an election. Espescially after the Deep State tried to frame him. He is allowed to fight back and question the legitimacy of people that intentionally, and continuously, lied to smear him.
Remember, they were already violating Trumps civil rights before he decided to run for election. They were illegally spying on him, and no one was ever held accountable. Trump has every right to think they stole the election, because they did.