Why is it always you three?

Harry Potter

Harry Potter, Ronald Weasley, and Hermione Granger are the main characters of Harry Potter. In Star Wars (at least the original trilogy), the main characters are Luke Skywalker, Han Solo, and Leia Organa. The three people have similar personalities as well.

Princess Leia and Hermione Granger are the brightest and most sensible characters among the six. Han Solo and Ron Weasley would be awarded for being the thick-headedest, as well as for providing some comic relief. Harry and Luke are no doubt the protagonist of each franchise, but they also serve as our main perspective. We’re introduced to the fantastic realm through Harry; Luke goes beyond Tatooine, and so do we.

You could also make the case that Anakin, Padme, and Obi-Wan are the three protagonists in the Star Wars prequels, with Rey, Finn, and Poe being the main characters in the sequels.

Fantastic Beasts, the Harry Potter prequel series, has four characters in total, although it may be down to Tina, Newt, and Jacob in Fantastic Beasts 3.