There are certainly people who claim to be seers. But scientists only accept such things when they can observe and record the act under what we call “controlled conditions”. That means we can control the factors in an experiment to make sure the people are not cheating or tricking us, or that their success is not just due to random chance.
As far as I know, no one has ever been able to demonstrate clairvoyance under scientifically acceptable controlled conditions.
If a person makes enough predictions of stuff that’s going to happen, chances are they will be correct some of the time. Seers and other people who say they can predict stuff usually make a lot of noise about when they get it right, and just don’t mention all the times they get wrong. Like Darren, I’ve never heard of a study where people have been able to get scientific evidence for being a seer or predicting the future.