That's what I'm saying to this : No. Entire history of businesses tell us about it. Coca-Cola was created in 1886 then several years later another carbonated soft drink, Pepsi-Cola, was introduced by a competing company. Was a unique drink that haven't been seen before? Hardly. But it's a thriving business, thriving to this day. The revenue of PepsiCo was more than $9 billion USD in 2023. And that's just one example. Surely, such approaches also work in the realm of gambling. You can copy everything from a well-known gambling site and make just some tiny changes, say in color palette and house edges of some games and voila, a new site is born. Will it be successful depends on many things but its uniqueness is of a minor importance.