Lebanon has a weak government. I think you could compare it with a house owner who does not have the means to evict uninvited guests, where the guests are much stronger and more powerful than the owner. This is both because the country consists of many ethnic groups and religions, and because it came to host a lot of Palestinian refugees and became base for the HQ of Palestinian resistance. Add on top of this widespread corruption. The situation is pretty dire.
Hezbollah considers that they must fight Israel following the Gaza war. They’ve stated they won’t stop until the Israelis leave Gaza.
The average Sunni Muslim in Beirut either remembers, or has family who remembers what happened during the (unprovoked by the Lebanese) Israeli invasion and subsequent occupation. Today, most of the Arab world supports Hamas in the Gaza war, considering that the large number of civilians being killed is essentially mass murder. Mix these two informations, and you will find very little trust towards Israelis. Add today’s attacks and things get even worse.
It’s very easy to destroy trust, and very hard to build it. None of this has to be perfectly logical - it’s not how people work.
I didn't say that the invasion didn't affect many Lebanese. Only that the Lebanese don't need to "resist" Israel, because it is not a threat to them, so long as they're not attacking it (or are in close proximity to those who are).
Hezbollah are not Palestinian. They're Shia Lebanese. And they're engaging in warfare against Israel with no provocation.
Israel responds by targeting Hezbollah weapons, assets and militants.
That doesn't explain why the average Sunni Lebanese in Beirut would feel like they need to "resist" Israel.