As far as why they were so enjoyable, I’m not entirely sure, but I have a theory. Those scenes are likely less CGI heavy than, for example, the Parademons fight in Justice League, and ergo feels more real. Big superhero showdowns are nice, but Warner Bros. needs to strike the balance Aquaman did with finding ways to keep the action going while altering the scale. It mixes things up and may actually make the big battle sequences feel bigger when they happen.
Article source: https://www.cinemablend.com/news/2464451/7-things-aquaman-did-well-that-the-dceu-should-continue-to-do-in-future-films