If the technical mechanisms and capabilities displayed in the action scenes, including fight choreography, that we see in Solo Leveling were commonplace or even occasional, I think that you would have more room to stand. But sometimes Anime of the Year isn't about story, world building, character design, or source material - it's about bringing anime into a new era of technical capabilities. Similar to award winning Avatar, which James Cameron developed, built a world for, created unique characters, and so on but created the movies around new developments in cinema technologies and post production capabilities. Sometimes these behind the scenes aspects are part of what makes a work of art so amazing. This is especially the case for Solo Leveling which does so while being one of the few adaptations of source material from outside of Japan. Also, the score was fantastic, including both opening and closing themes. This is extremely impressive and it is why many fans chose to vote for it, myself included, not because of the power leveling. And to call the cinematography, animation, and other technical innovations and everything related to the sound/music "surface level" is wildly inaccurate.

7 Deadly Sins has a magnificent story and world building - but as you said, that's thanks to the manga.

I watched the anime as much as I could due to loyalty, but I think most viewers and A-1 agree that it is maybe one of the biggest anime failures of majorly popular source material ever. And why ?

The animation quality was abysmal, as you also stated.

This author either doesn't actually watch anime or read manga, is AI powered, or is writing rage bait.