It's fun if you've got a high tolerance for gross bullshit and can enjoy laughing at the show. SAO is weird because in its later arcs it's like the author is earnestly trying to not be awful, but he still fundamentally doesn't understand technology, video games, people, or cause and effect, so it ends up in this weird space where it can be wildly problematic but then have better themes than most anime and center its female characters as the ones with agency who are driving all of the plot, while still being an absolutely nonsensical story that hinges on plot points that fundamentally just do not make sense or work at all.