@umpteennamechanges nailed it I think. You could pay a lot of money for that advice.
On luck...
Luck determines where you start from and to some extent the tools you will have.
So if you think of "success" like a finishing line that is the same for everyone, generally the people who get the biggest head starts will be the winners, and most of the people who start far back never even make the finishing line. Some people start so far ahead they can go backwards and still finish way ahead of most people.
That is one way to look at it, and it's totally valid. For example, if you are thinking about social structures and fairness and how society should work best, a model that looks across everyone is the one you need.
But you can also think of success as how far you get from where you started. That's where the hard / smart work, the grit and the soft skills come in to it. And when you look at that measure, you can absolutely see that what people do will make them more or less successful. You can also see that "better" doesn't have to be the same for everyone - it could be richer, but it could also be healthier, or doing work you value, or having time every day with loved ones.
This measure is also valid, and it's the right one to think about when you want to be successful in your own life.
You can't have someone else's luck. So you can say it's not fair that people start with advantages and you'd be right, but it shouldn't stop you from taking steps to making your own life better.
The other thing about luck is opportunities. Again, if you start from privilege you have more opportunities. But the other thing with opportunities is that each one you take opens up new ones. So if something comes along and you don't take it, you stay where you are hoping another one turns up. But if you DO take it, you move to a different starting point and opportunities that wouldn't be available to you before are now. (Of course, there may be opportunities that were open to you before that are not any more. But if you'd wanted them you'd have taken them already, so chances are you'll get more out of the new ones opening up than the old ones closing). So opportunities are partially luck but also partially how you respond to them.