Iran has four times the land area and over three times the population that Iraq did at the start of Bush Jr.'s war, plus they've been preparing for an invasion by the U.S.
specifically since 1979. Bush assembled a large coalition of many allies to share the costs, but the U.S. is still struggling with the debt that resulted from the second Iraq war. A land war in Iran would bankrupt the U.S. and the Iranians know it. Occupying the entire country is also the
only way to secure the straight of Hormuz by force, because every part of Iran is within drone range of Hormuz. For the IRGC, this is a threat to their very existence. They are very much on what Sun Tzu would consider "desperate ground". For the U.S., this invasion is a "wag the dog" operation that is devoid of concrete policy goals.
To put things in Trump's parlance, Iran has the cards and the U.S. doesn't. If Trump is going to declare victory and TACO, he's going to have to accept Iranian control of Hormuz and pay for the passage of ships. This is going to take epic levels of reality distortion to sell as a win, but the alternative is far worse.