Books, music, films, games, basically all creative things. Because everyone can just watch/read/listen to the best of the best. It's not like restaurants where the consumer actually consumes the product.
It's the result of global scale distribution networks. Long ago you could be okay-famous by being the best guitarist in the village and people would appreciate you. Or you could be the local history buff. But if you write enter the global arena, you'll compete with everyone else. There's no limit to how many books the famous author can sell, or how many times a famous singer's song can be streamed on Spotify. There's simply very little demand for mediocre stuff. Also, people want to be able to talk to each other about cultural things. Even if it's a bit more fragmented today, people still want to belong together through liking the same things.