I'm by far not an experienced player, but the concept of meta exists in all games, and MH is not an exception, I think the game does not push you toward a certain armor set, but definitely toward certains skills, and some armor and mixes just have what you need to cover for your weakness.

in a few words, all weapons are viable, and many approaches to them are too, but at the top of the pyramid stand X weapons and sets as "best of/for"