This show is an abomination. It tries to come off as a serious show at times with a structured story but nothing at all matters. Ninety percent of the content in the first arc, Aincrad, seem like filler with no real reason to be included in the show. Not to mention the parts that do matter, make no sense at all. The author, even though making a show about video games, fails to make a game that would even seem like any fun to ever play. The game is filled with terrible mechanics and design. With the game being the main setting of the show, it should be well constructed but there are mechanics such as randomly attainable skills that only one player can have at a time, which of course the protagonist gets a really broken one. Asuna was a decent character at the beginning of the show only to be written off as a damsel in distress in the second half of the season. She was built up to be the one person as strong as Kirito but she, for some reason, maxes her cooking stat and also has absolutely 0 altercation with Kirito at all. Kirito has moments when he seemingly is supposed to learn something or some lesson but then it never actually matters. The author uses lazy attempts to create plot points or create shocking moments with rape, which is really low-level, and cheap writing which occurs in almost every single part of the show. The logistics of the second half also make no sense. Realistically, after the royal disaster that was Sword Art Online, no company would touch that medium with a thousand foot pole for many years, let alone the public ever wanting to play any game. The plot point with Kirito and Suguha was very poorly done. Incest is almost never a good idea to write about without it being a trashy show, but it is definitely possible to make it work. However it is a failure in this show, where it drags on too long and it doesn't really seemed that Suguha learned that it was wrong in the first place.
Perhaps the absolute worst part of the show was the introduction of the character Yui. She actually serves zero purpose in the show other than to be a kid for Kirito and Asuna when they marry, and as a convenient plot point whenever they need some infiltration or game info for whatever reason. She can access anything she needs to at any time and acts as a vehicle for deus ex machina. She had an attempted sad passing where she turned into an item, then somehow gets transferred to other games which should have no connection to the Aincrad realm, and even into real life applications. She has to be among the smartest AI created but for some reason she is in a game that had a limited run of like 10,000 people.