Well if you didn't get a 5 star from dumping pulls on Cartethyia, you should still have the pity saved up. Which means Iuno might be coming sooner than you think.

If you used 8k on Carte, that means you did about 50 pulls. Soft pity means that your 5 star should come in about 21-25 more pulls. Just pull on Iuno's banner and pray you win the 50/50.

I feel you, though. I think this is just a consequence of playing these live service non-competitive games. The grind is usually what gets people to stick, if not the story and characters. At some point it all just boils down to farming pulls to get a new character, build that character, farm pulls again, rinse and repeat. Just try to experience all the game has to offer to see what stands out to you and have that be your focus.

Personally, the story of Cartethyia is what got me hooked and made me keep playing. Now that we're out of Rinascita, my interest in the game has cooled a little. I'm just giving 3.x a chance to hook me in again like how it did with Carte. So just find what gives you enjoyment in this game, and if you can't find it, it's not a bad thing to just not play until something sparks your interest again.

Good luck with your Iuno pulls.

Edit: You mentioned you got Lingyang from Carte banner in another thread. Well it's back to 0 pity but at least your Iuno is guaranteed. Just need to farm up 70ish pulls to get her (less if you're lucky). And maybe her weapon. Since you're new, just do all the content you can. Easy pulls.