This has really great animation overall. It is a classic shonen style with a modern twist that isn't too modern or odd so it feels really comfortable to watch. Art style, sounds, phrasing, and all that follows tradition but also has been updated and maybe centered a little more around a western perspective. The storyline is complex and keeps you engaged. Character development is on point, and a lot of effort is put into really giving side characters whole personalities. There is a really nice blend of themes here but overall sticks to the action/dark theme which is one of my faves so it is a great watch.
EDIT: Ok the new series is not finished yet but I really had to jot this down - boy oh boy is is getting dark in here!!!! AOT started on dark notes, don't get me wrong, but still did a good job of maintaining the balance, innocence, and sort of hopefulness that shonen calls for. As the storyline has matured, it has developed into this deeply devastating experience with innocent moments sprinkled in for added flavor. It almost feels like watching a young kid's trauma turn into an adult's untreated mental illness lmao. If they end the series this twisted, this show may skyrocket to my top three list.
Edit edit: GOAT