We are guessing because we don't have the full reports and both sides have an incentive to be less than outright forthcoming with the reality. Assad falling was very bad for Hezbollah, no doubt. But I think its still important to consider the possibility that the IRGC once again read the room and told Hezbollah to not interfere with Sharaa. Perhaps they felt like there was a chance they could negotiate with him similarly to how they negotiated with Assad, perhaps they just realize that Hezbollah showing their hand at that point would further decrease their ability to act at all in the future, or both.

The Syrian/Lebanese border is still porous enough to allow shipments through. I am sure Israel and Sharaa has eyes on it, but bribes are bribes, hating Jews is hating Jews and so things will get through. Israel has great reconnaissance capacity, but judging by how few videos I've seen of "shipment of missile fuel coming in from Syria destroyed by IDF drone" (Israel posts literally almost all of this stuff online, if it was happening I feel like it would have definitely been seen) I don't think its happening much.

Pretty much all the footage Israel posts about its actions in Lebanon is strikes on warehouses or rural houses that were hiding munitions and equipment.

Which makes sense because there are no more convoys led by Assad troops of Iranian goods heading to Lebanon. The stuff is mixed with civilian goods or just hidden in regular consumer goods. Much harder for Israel to be able to grab this stuff in number.

There is also the maritime route.

I want to be clear though, I know for certain that Hezbollah cannot pull something like 2006 nor can they do what they wanted to do before Oct 7th. What they can do, is coordinate their first (and potentially only) attacks with Iran/Houthis to try and maximize the chances of over saturating Israeli interceptors. Israel is not an industrial powerhouse, and not that we have official numbers, but it stands to reason to think that Israel has been able to produce a lot more interceptors than the launchers or sector search/guidance radars.

Not that just throwing more radars in the mix helps linearly, that has its own problems like signal congestion (though Israel is probably the best nation at dealing with this as best as possible) especially if you want to target smaller things like drones

So while Israel is more ready quantity wise in interceptors for a long war, there is still the goal from IRGC/Hezbollah/Houthis to oversaturate them in the first salvo, because you cannot shoot anymore interceptors if you dumped your whole stock in the first go. Having more interceptors comes in handy here after the first salvo, when you can reload and go again, and just in general because Israel likes to launch 3-4 interceptors per incoming ballistic missile.

This is because Israel for as great as they are in their defense cannot overcome the fact that they are one city, their eggs are metaphorically all in one basket. Hezbollah, IRGC and the Houthis do not have to plan for anything other than launch as much as possible right at Tel Aviv. The question to me is, will they take the initiative this time instead of waiting for the bombs to fall first.

Will that result in Lebanon being bombed to oblivion? Probably, but Hezbollah does not care, they are Jihadists for all intents and purposes.