Yeah, I have friends who are millionaires. I have friends who are famous. (I don't have friends who are powerful... never ran in those circles...). All of my rich friends either inherited their money or won the DotCom lottery. All of my famous friends worked their butts of in obscurity for decades and then won the Celebrity lottery.
None of them are happier than me as far as I can tell. (And, yes, I can afford another pair of trousers, but who needs 3 pairs of trousers!?).
Fame, wealth, and power are only loosely correlated with happiness. They are neither adequate, nor necessary.
If you count success in life as buying a house with money you were given, great. But that isn't success. I don't even know what that is honestly.
The middle class is disappearing. Either you know how to make money (and that's not by working a job) or you don't. If you don't, you'll eventually be replaced by software, or a robot, or your job will be optimised away, or you will have to compete with 50 other people who want the same job because less jobs will be available in the future.
The only thing that isn't disappearing is having great ideas. Great ideas, combined with an interest in executing, generally lead to freedom in life and (some) wealth.
It really depends on how much you inherit. If you inherit a million dollars, yeah, it's easy to spend it all. If you inherit a billion, it's not hard to sit on that money and live off a fraction of the earnings. Which is why major familial wealth tends to stick around for generations. (That and the connections that major wealth can provide.)
My personal opinion is that most people should be able to make $100-200k on their own online, doing something they love. If you actually start looking with what people are making money with, it's pretty interesting. This can range from a recipe subscription to a newsletter, or something completely different.
Will it be easy? No. Will you be able to live a free life? Yep.
BUT: there has never been an easier time in history for someone to make money on their own.
Edit: I fully agree that it's easier than ever to build wealth from limited means.