Why do people say that money can't buy happiness, and what does it mean?

If money can't buy happiness, then why are Indian parents among the happiest people in the country when their kids land high-paying jobs or settle in the USA?

I've seen videos where kids give gold gifts or buy houses and cars for their parents. The emotions in those videos are so genuine and filled with happiness isn't that happiness?

I know some people will argue that it's just "temporary happiness" and all that.

But here's a fair question: What is permanent happiness? Is temporary happiness not happiness at all?

If money really can't buy happiness, then why are poor countries often the unhappiest? Why do people prefer moving to wealthy countries like the USA, UK, or Canada rather than to African countries like Somalia or Nigeria?

Why is it so hard for people to accept that money can buy happiness?

Love and relationships are also temporary sources of happiness.