As Bob Dylan said 'money doesn't talk, it swears.' It's a powerful thing, some people have too much of it to ever know what to do with, others hardly have any and some people can never have enough.
What is undeniable is that the more you have the more options you have available to you in life. That isn't necessarily going to make someone happy though. Good health, self fulfilment, love, friendships, interests etc are all more likely to make someone happy but adding a reasonable amount of money to the mix can certainly make life easier.