The Iranian regime is a revolutionary regime of revolutionaries who want to spread their revolution.
If the West wants to send them stuff for free, they'll take it. That's less they'll need to divert from spreading their revolution.
Any generosity to Iran is akin to supplying the Bolsheviks the rope they'd use to hang us.
They are a nation blessed with natural resources and an educated population. They have potential to be a great nation, but, instead, they divert all their resources towards spreading their Revolution. The US and Israel are their enemy because those nations are preventing them from conquering the entire Middle East.
They have also have their sights set on any other nations that would rival them for power and control in the Middle East - Saudi Arabia, Turkey, and the United Arab Emirates.
The strategic objective of backing the Houthis in Yemen was to create a pro-Shia, pro-Iran satellite state that could threaten Red Sea maritime commerce and foreign Red Sea naval transits. It was also hoped that a Houthi-controlled Yemen would be a destablizing force on Saudi Arabia's southwestern border.
The revolutionary regime of Iran has no interest in anything other than spreading their revolution and increasing their power and influence in the region - displacing the United States, Israel, Saudi Arabia, the United Arab Emirates, and Turkey, with a watchful eye on Russia.