We know what the rates of failure are. We know that studying hard does not guarantee success and what the level of risk is.
We have no idea how many people tried to do the same thing as highly successful businesses and failed. We know that luck or resourced (initial funding, contacts, timing) not available to most people have played a part in many success stories. We know that things could have gone badly wrong for them (e.g. Richard Branson's family had to put up a lot of money including a £70k fine to avoid a prosecution for tax dodging). We know that the rate of failures in businesses (especially ambitious high risk high high risk high reward ones) is far higher than in medical school or law school.
All that makes survivourship bias a lot more relevant
The advice may have merit, but survivourship bias means it is not more credible because it comes from someone successful than the same advice from a random person.
We have no idea how many people tried to do the same thing as highly successful businesses and failed. We know that luck or resourced (initial funding, contacts, timing) not available to most people have played a part in many success stories. We know that things could have gone badly wrong for them (e.g. Richard Branson's family had to put up a lot of money including a £70k fine to avoid a prosecution for tax dodging). We know that the rate of failures in businesses (especially ambitious high risk high high risk high reward ones) is far higher than in medical school or law school.
All that makes survivourship bias a lot more relevant