For Sunni Salafists like the ones who ousted Bashar al-Assad, the Palestinian cause does not take precedent over purifying Mecca and Medina of so-called "impurities" or "corruption."
More important for these combat jihadists is defeating heretical regimes (meaning Shia Islam-led countries: the Shiite Crescent.)
The loss of Syria reduces the Shiite Crescent by one, leaving Iran, Iraq, Azerbaijan, and the Yemeni Houthis. Shia minorities in Central Asia and Pakistan are geo-politically ineffective but subject to Sunni persecution (like the Hazaras in Afghanistan).
The unresolved Yemeni Civil War is between Muhammad Bin Salman-backed Sunnis versus the Shiites. In 2015 when the Yemeni Shiites (AKA the Houthis) defeated and humiliated the Saudis and Sunni Yemeni army, MBS ordered an air and naval blockade of Yemen.
This inhuman blockade lead to a famine which the UN estimates killed 130,000 Shiites.
Hashem Mahmoud Atin, a 10-month-old displaced child suffering from acute malnutrition and who is unable to reach a hospital for treatment, is held by his mother at a refugee camp in Yemen.
When few countries helped the Houthis, Iran and Lebanese Hezbollah (their fellow Shiites) stepped in with massive food aid and arms. Out of gratitude and loyalty, the Houthis became proxies for Tehran and Lebanese Hezbollah. This is why we see the Houthis counterattacking Western maritime targets in the Red Sea or the Gulf of Aden whenever Israel attacks Iran, LH, or Syria. USCENTCOM then retaliates or conducts pre-emptive strikes against the Houthis. See CENTCOM press release below on one of their latest strikes.
Note: Shiite Hazaras bravely fought alongside US forces in Afghanistan.
Undated photo of elite Hazara soldiers courtesy of the Washington Post.
Sources:
https://www.timesofisrael.com/islamic-state-explains-why-it-doesnt-attack-israel-yet/
https://www.centcom.mil/MEDIA/PRESS-RELEASES/Press-Release-View/Article/3963942/us-central-command-strikes-houthi-facilities-and-weapons-systems/
https://news.un.org/en/story/2022/03/1113852
https://en.wikipedia.org/wiki/Sectarian_violence_in_Pakistan