Either something seems really amiss, or the invasion of and war in Ukraine has weakened Russiam forces in Syria such that it is not as much help to Assad as it once was.
But no one should celebrate the fall of Assad. Whoever comes out on top after his ouster will be worse, worse for the west, worse for Israel.
The proximate cause is the collapse of Lebanese Hezbollah, smashed by Israel. Assads perennial problem has been manpower, as Syria is majority Sunni. Iran has been providing Shiite troops recruited by its puppet Hezbollah, as a major part of the Syrian governments infantry. It seems that last week all or most Hezbollah troops just went home, apparently the result of a collapse in morale, leaving the frontline unmanned or undermanned.
It was the Iranian-provided infantry that were critical, not RuAF assets.
Russian forces in Syria were just some specialist and support formations. Without the manpower to hold the front all the remaining Syrian forces can do is retreat. You cant hold the line with just airstrikes.
I’m thinking Russia is now a paper tiger military with the exception of nukes. They have no navy, no aircraft carrier to project power worldwide wide. The admiral Kissoff is basically an artificial reef.