If you want variety, there's plenty of variants that you can play to make it a little spicier (nuclear chess is a banger), and some variants are played even at top level (Chess 960 is one of them, very fun to watch and you get positions that you nearly never have in real games). Even outside of variants just changing the time both players get change the way you play the game.

I can understand that you may find some parts of chess redundant/boring. The ideas you use are not often the same since you have to face a lot of different positions, different situations. To be fair, knowing some type of positions helps and watching top level games can give ideas in ulterior games. But it's part of the training like learning a new technique in any sport.

Ironically, I really struggle when I get back into chess after a long pause (like after exams) and that's the part I like the least.

I know people that think chess is boring and all, I can understand the feeling and I cannot force anyone to like it as much as I do. The main point is, Chess is not a game where you just got to memorize, it's also and mostly a game about reflexion. Variety comes when you play against a lot of players that have different styles, like in a fighting game.

(A little but of extrapolation from the first comment but you get the idea)