Is being a sci-fi writer a viable career path? i know its not secure if im not

[DionneMais]

that successful but im imaginin? do successful sci-fi writers make money? enough to live on without other jobs. what medium is better to concentrate on? short stories,novels,graphic novels/manga or scripts. is it a hard living even if successful? has any sci-ifi writer ever sold a million copies in a year? what volume of work should the average and/or successful sci-fi writer produce in a year to live well? all thoughts are welcome. thanks