these seem to be the reasons
"I’m just an ordinary person now, so I’ll be honest.
The reason I left my previous band is because, except for me, everyone else was doing playback during live shows, they didn’t practice, and on the day of the dress rehearsal before our important one-man final, the vocalist said to the staff, ‘We don’t need five hours for this, right?’ That was the last straw"
“For me, the thing I hate the most is continuing a band out of inertia without any ambition. It’s also disrespectful to the fans.”
“If you openly say ‘We’re an air band!’ then that’s actually super cool. But saying ‘We’re a band!’ while essentially being an air band is just the lamest thing ever.”
source: https://x.com/reika_drum_0228/status/1914149189547606380?t=hQ5GPZC94hfa9q3dcX_qTw&s=19