I've played a lot of arcade Beatmania(mostly BMIII/BM the Final) and I can say that while this does play BMS files, it's not an ideal experience - web browsers

I've played a lot of arcade Beatmania(mostly BMIII/BM the Final) and I can say that while this does play BMS files, it's not an ideal experience - web browsers have not prioritized audio latency historically, which is crucial to music games with keysound feedback, and on a touchscreen, there's no tactility so you're going to lose your finger placement a lot. I do play and enjoy Taiko-web from time to time, though. It is possible to get it good enough for casual play, especially with lenient judgment.