You should look at the broader picture.
Over the last 1,5 years from Iranian part we saw:
1) Attack against Abqaiq oil facility (which was like an open declaration of war)
2) Attack against oil tankers in the Persian Gulf (another declaration of war)
3) Harassment and attacks on US bases in Iraq which at one point killed a US contractor
4) Attack on US embassy in Baghdad
5) Downing of US drone
6) Downing of US plane in Afghanistan
7) Ballistic Missile attack on US bases in Iraq with property damage and injuries
8) Houthi attack on Jeddah oil facility during the recent meeting of MBS and Netanuyahu
From US part we saw:
1) Murder of Soleimani
2) Explosion in Natanz
3) Recent murder of a retired nuclear scientist
Probably, just like murder of Soleimani was a direct response to bold Iranian attacks against Abqaiq and oil tankers---this murder of a nuclear scientist is a direct response to recent Houthi (Iranian) attack against Saudi oil infrastructure in Jeddah couple of days ago
On the broader strategic level we see formation of two military blocks in the Middle East: Iran-Iraq-Syria-Hezbollah-Houthis AGAINST Israel-Saudi Arabia-UAE
Israel can take care of Syria and Hezbollah,
Saudis and UAE can try to take care of Yemen.
But when it comes to Iran vs Saudi Arabia ---Saudis can't protect themselves without Americans. Iran constantly harasses Saudi Arabia by showing vulnerabilities of Saudi oil infrastructure and reminding that Shias of Saudi Eastern province can rise against Saudi regime with Iranian support as US reduces number of forces in the Middle East in the near future.
Saudis are terrified that as Biden signs a deal with Iran and reduces number of forces in the region and pivots to Asia--Saudis will have to remain alone with Iran.
And though Trump administration was heavily influenced by Zionist elements---with development of US shale oil industry and energy self-sufficiency of USA, Biden can decide that US no longer cares about the Persian Gulf and needs to sign a deal with Iran, withdraw from the region and pivot to Asia leaving Saudis alone against Iran