A strong pick is Primal : it is a 2020s American adult action cartoon that is serious, visually stunning, and far less cynical than Rick and Morty while treating emotion, survival, and violence with real weight. Another good fit is Castlevania and its follow-up Castlevania: Nocturne if you want dark fantasy action with respect for character drama rather than snarky meta- jokes; however, those titles weren’t surfaced in the current results, so I’m keeping the recommendation focused on the verified options here.

Best match

  • Primal — the clearest answer for “non-comedy adult cartoon action” in the 2020s, with simple storytelling, intense action, and a sincere tone.
  • It stands out because it uses animation for mood and survival rather than constant irony or self-aware jokes.

Also worth a look

  • Harley Quinn — still adult and action-heavy, but it is much more of a comedy/parody than the kind of respectful, non-cynical show you asked for.
  • The Boondocks — sharp and influential, but it is satire, so it does not really fit the “rejecting cynical meta” part of your request.
  • Space Dandy and Solar Opposites are closer to absurd sci-fi comedy than to sincere action drama, so they are weaker matches for your specific taste.

What to prioritize

  • Look for shows that are action-first , emotionally direct, and light on parody.
  • In practice, that usually means prehistoric survival, fantasy combat, or grounded adventure rather than multiverse satire or joke-driven sci-fi.

Best one-line answer

  • Primal is the best 2020s American adult action cartoon I’d put ahead of Rick and Morty on sincerity, respect for the audience, and lack of cynical meta-humor.