Trade contains risks, and if the trade is profitable and guaranteed, why does not everyone trade? Any investment involves risks. In general, the risk is commensurate with the profits, and the least is what you get from banks. Even these bank deposits may involve risks, although they are very low.
In mind your own business (MYOB), I care about customer satisfaction, continuous return even if it is low, the possibility of converting the commercial activity to another activity without large costs, you have a job or it is easy to get a job if this project fails.
Beware, guaranteed profit is often associated with a Ponzi scheme which is a scam.
What kind of La La Land are you living in where any business that's started today is guaranteed to make money the next day, it might be true to some level but I don't think that it's a real thing,
I think it is the salt trade, where you bring sea water, suddenly it becomes salt and you sell it.