I think that's not fair to say Lebanese people don't get along and want to be part of Syria. It's a diverse nation that has potential if reform and security arrangements are made.
It's tough for Hezbollah as some will blame Hezbollah's exisistence for that.
But major players are also not equipping the Lebanese army. Means there is some kind of agenda to keep Lebanon weak. Either major players with money hold the view that Lebanon should be Syrian or for other reasons.
I would not want to be a part of Syria as a Lebanese person. Lebanese didn't want to be part of Assad family ruled Syria either. The country is occupied and in ruins, there's no actual reconstruction happening funds aren't there or projects are being delayed.
It's a complicated dynamic given all these factors. I imagine Shia's don't feel safe either. And there isn't trust in the Lebanese army because they're weak and not properly equipped. Everyone in Lebanon has weapons or formed militias in the past. Palestinians, Shia's, Sunnis, Christians, etc ....
So if the major players were actually interested in Lebanon prospering, they'd properly equip the Lebanese army or allow it to purchase more effective weapons + increase in size to be able to establish law and order in the country, but they aren't
How is it not fair when they have had the longest civil war in modern Arab history which was only brokered due to immense KSA pressure and threat of KSA economic boycott? Hence the later Taif agreement.
How is it not divided when their entire political system is divided and positions in the government (foreign minister, president, prime minister etc.) are divided by sectarian identity and can only be held by either Shias, Sunnis or Christians? For instance only Sunni Lebanese can even become prime ministers.
How are they remotely unified when they cannot even coexist? Have you seen the pathetic state of the Lebanese political system, their collapsing economy (not due to Israel or any outsiders) the corruption, lack of any industry etc.?
It is a completely failed state due to its inherent divisions.
The country was close to a civil war during the Syrian Civil War itself. You had 10.000's of Lebanese Hezbollah fighters fighting on behalf of Al-Assad in Syria while you had similarly 1000's of Sunni Lebanese fighting on the side of the Syrian opposition.
Lebanese were basically killing each other in a foreign country (Syria). I do not know of any such examples maybe outside of Iraqis and Yemenis who you also could find on both sides.
Nobody (regional countries) has any agenda to keep Lebanon weak by default because Lebanon is largely and irrelevant country regionally speaking both militarily, economically and politically.
The only country that has a direct interest in a weak Lebanon is Israel.
I am not talking about now, both Syria and Lebanon are failed states as of now. But historically speaking Lebanon was always part (for the most) of historical Syria and it was carved out by the French for the Christian community hence why Lebanon was/is heavily Maronite dominated politically to this day.
Maybe if the Shias had not stupidly attacked Syrian Muslims for no sane reason other than following Iranian regime blindly in order to protect the Al-Assad rule, there would not be this animosity between Syrians and Lebanese Shias.
Israel/US is not going to allow the appearance of a strong and anti-Israel Lebanese army or any such group.
Which is why it is thanks to stupid Lebanese divisions that the past 50 years of division has even prevented them from having a powerful inclusive national army where people like Hezbollah foot soldiers could easily serve and join.
Trying to remove any blame from Hezbollah and its leadership for the divisions within Lebanon (which they are a main reason for) is not serious.