Yes, Hezbollah was propping Assad up. They actively intervened in the civil war on his side and were responsible for several mass atrocities in Syria including blockading villages to starvation and mass executions. They have been involved since the very beginning of the conflict in 2011.
https://en.m.wikipedia.org/wiki/Hezbollah_involvement_in_the...
The first, chronologically, was US led sanctions in 2011 that froze government assets and prevented almost all import/export with the west. [1]
The 2nd was military conquest and occupation of 90% of Syria's oilfields since 2016/17, Which the government relied on for 40+% of the national budget. Without money, it struggled to pay and supply the army. [2]
The last was tying up Russisa, who was the regime's patron and military supporter, in combat in Ukraine.
https://en.wikipedia.org/wiki/International_sanctions_agains...
https://www.washingtonpost.com/world/middle_east/us-led-coal...
Fifty thousand people are dead, many of whom were underage, and most of the universities and hospitals in Gaza are destroyed. Like the Iraq war or Tianamen Square, this is something people are going to keep bringing up for decades.
Syria is arguably the only good outcome, and it's not clear whether that was anything to do with Israel/US action at all?