Everything about AoC is superior where it counts. The story canonically fits within the story of BotW (albiet an alternate timeline), and therefore feels more genuine as a result. Each character feels unique in AoC, welcoming somewhat different options for play style. The level design feels a bit deeper than your typical warriors game as well.
The first Hyrule Warriors just felt like a celebration of the IP, while AoC feels like an actual entry in its own right...just with Warriors gameplay instead of being an adventure/puzzle game.