In every business, save a monopoly, one can expect competition. A wise entrepreneur would do research before proceeding. This is more ‘spying’ to see the faults of the other business.
As supermarkets are well known to all, I will use them again as the example.
If it is possible to find an area where there are no such businesses and be able to create one, then, unless one is a terrible business operator, success is likely.
Where one opens a business which will compete with others in proximity then a constant need to ‘spy’ and insure that the business is filling gaps the other has, or able to offer lower prices, or some incentive to capture customers.
Older businesses have armies of spies and see things that many new owners do not.
How the products are placed, the convenience or not of specific items, the number of cashiers, shelf packers, baggers and the like, etc. are vital to a business.
And being aware of the situation allows the managers/owners to take action before something happens.