Money can't buy happiness, it can only buy comfort. Having more comfort can make it easier to find true happiness. However, some people who are poor and live in tough situations can still find true happiness, just like how some rich people who buy all the material goods they want can still feel empty inside. I believe that having a support network of family and friends is more important when it comes to being happy.
I agree when you say there is an important factor on having good family and friends when comes to reaching true happiness and there are indeed people who are genuinely happy who does not have as much as millionaires or billionaires.
The thing with money and having much of it though, is that one is always in purpose for more of it and the immediate satisfaction it brings: luxury cars, big hotels, nights in casinos, deluxe dinners in Las Vegas, among other things.
In the end of the day, if one has everything and there is nothing to pursue, emptiness starts to appear within the self. We all need a reason to live for and a dream to pursue, even after reaching that, we set another aim to look forward to and so on.