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.
I recently started to realize the same thing. I've seen new games that take inspiration from existing mainstream games but they manage to survive because the production value is quite OK while the story and microtransactions are not as bad as others copycat. While characters are similar, they are distinct enough so they can avoid any plagiarism issues. I guess marketing plays a part in how the market perceives your product.
I am not sure how the community experience is going to play in betting. It tends to be a bit more of a solo activity in general unless you are specifically betting with friends among yourselves - which does not require a site or an intermediary. Perhaps creating the community in this context is going to be the main challenge and will require very experienced mangement.