someone you know who smokes way too much but won't drop the habit how would you approach this?
Think of it this way. Replace anime and smoke together. If you were to convince me to stop watching anime, telling me "stop watching it" would leave me kinda empty. I'd more easily let go of anime if you introduced me to something equally or even more entertaining to replace that emptiness with. I dunno... a tv show perhaps? But it doesn't necessarily need to be the same kind of thing. Anime and tv shows are both things you watch. If you keep me busy by having me spend more time participate in some sport with you and other friends, or even an online game, then I would have less time for anime.
Tbh I've never had to deal with a situation like yours, so that for you to figure out. It's basically more about deviating them from what they're doing instead of straight up stopping them. Would feel less forced and more natural.