Ridiculous number of weird repetitive videos?

I randomly was recommended a video of this channel that mostly seems to upload the same old video of a group of teenage girls singing with weird popups talking about "no school" or sports matches. The earlier videos on the channel have the videos original audio but the later ones don't seem to. Some have odd sounding voiceovers or ambient audio. They also upload other weird things, most of which seeming to have some relation to getting 10,000 steps? Occasionally they even post normal gameplay of like Mario Maker. I found one video that seemingly has the actual person behind the channel in it and they certainly don't seem like any of the girls in the video they post so much. The most absurd thing about the channel is the sheer amount of these videos. They only started last year and yet there are so many, continuing to be uploaded. Here it is for those curious: https://www.youtube.com/@TeamMario-lb9wd
One of the vids I saw had a random loud noise in it so be careful of that.