Is success luck or hard work?

It can be both, it can be one or the other. Some people get lucky and don't put in much work, other people put in a lot of hard work and get places, some people put in hard work but get nowhere. It depends what your "hard work" is going towards. If you have no creativity or you have a bad idea or don't believe in yourself, no matter how much work you put in you could still get nowhere. Success is a mixture of things imo.