It's always a combination. I dont think people understand what constitutes as luck sometimes. I follow a business guru on Instagram and she gets very angry and defensive when the word luck is mentioned in relation to her success.
Anyone who is healthy, educated and mentally stable is lucky.
I have a friend who has mild learning difficulties, mild enough that unless you spent substantial time with her, you wouldn't notice. But significant enough that she would not be able to have a career, she doesn't have the problem solving skills, emotional intelligence, understanding of social conduct and organisational skills to have a career. Every few months I see her shes on about the next big dream, to be a film director, have a theatre school, to be a journalist or song writer. No matter how hard she works, it probably wont happen.
I have a family member who has an autistic son who is now 15. He requires full time supervision, carers, every outing he goes on takes significant planning as he is large and aggressive, he self harms and tries to choke himself. She was a dietitian before working on a career in research, the only possible way she could return to her career if he was to go into full time residential care.
I also know someone who it has taken them 7 years to complete a 3 year degree because they had epilepsy and spent half their week sleeping of a seizure. Shes got that far, but progressing much further is the next challenge.
Those people no matter how hard they work, due to the bad hand they've been dealt, will not achieve success in the conventional way and have not had luck on their side.
Everyone I know who is successful is not directly affected by illness, disability, trauma or poverty. Yes they work long hours daily, but they've never had anything stopping them working long hours and it's always been enabled and supported by those around them.
And theres always been an element of right place and right time. Out of the 2 most successful people I know, when one decided to buy a premise for their business at that exact time the most perfect and well suited location became available, any other year and she would not have had half the success. The other successful person I know works as a contractor offshore, he became aware of this job as a teen as he went on holiday at one of the stop off places the workers go to, he got chatting to some blokes, got some insider tips on these niche and well paying careers on the rigs, he then geared all of training to getting this particular role when he was older. Yes he worked hard, but had he never met these people who sold their life style, told him exactly how they got to where they were and how he could do it too, it wouldn't have happened.
Luck always plays a part.