>>1935
Everyone here is a shithead and refuses to elaborate or explain why you should watch anything, so I'll do it instead.
I think we need to define what K-on! means to you. Both K-on! and Bocchi are seasonal moe blob yonkoma adaptations that take liberties to develop a plot. The story of the first season both revolve around forming a band and looking forward to playing a cultural festival. And in the broadest sense, they are both "cute girls doing cute things".
But the major departure with Bocchi is how individual episodes are written. I would summarize the average K-on! episode as "the girls fuck around for 20 minutes and then stumble into success anyways to keep the plot going". They do absolutely nothing but procrastinate, and it seems more like the band thing is a gimmick for aesthetic reasons rather than an actual passion of anyone involved, including the main characters. Additionally, the protagonist starts from absolute 0, yet manages to play acceptable rather quickly.
On the other hand, Bocchi has some skill due to autistically practicing by herself for years, but has no ability to play with others or adjust her own timing to match, which is a barrier. However, every episode entails her and the gang doing stuff to further their ambitions. They have jobs at a music club where they work. They rarely even hang out as a group because their time is spent working or practicing when they are free. Money is an issue. Publicity is an issue. They have to earn the right to play on stage. They have to actually convince others to show up. It's not the highest stakes or the biggest struggle, but I would characterize each episode of Bocchi as being about "trying to make a band succeed". K-on! is fundamentally not about being in a band on any substantive level.
I think my biggest problem is that, yeah, a lot of Bocchi stuff has been done before. If you've seen K-on! and Watamote then it kinda feels like treading old ground. That said, I think Bocchi does it better than both of them. The animation is crisper (aside from one rotoscoped segment that could hide the CGI well) and more creative, and the main character shows actual growth. By the end of Watamote, Tomoko was still a smelly autist who doubled-down. By the end of K-on!, they're still procrastinating and using Mugi's wealth to fund their bullshit and have tea time. Bocchi actually learns and improves. Is it a major change? No, but she improves on both communication, social skills, and group performances over the course of the show, and that's more than I can say for most seasonal anime where nothing is learned and the characters are built to have the same gimmick forever.
Also bassist is best girl.