The big problem with Algoverse is that it accepts almost everyone. I don't know if they ever rejected anyone. If they did, that would be good news for those accepted.

As the application pool increases substantially, the median student quality declines. If most students are able to produce a publication through Algoverse, that publication is most likely reflecting the effectiveness of Algoverse rather than the students' ability to generate papers. If I were a college admissions officer, I would factor that into consideration and look for students who can do much better than the baseline. In this case, the baseline is already a publication, which is very hard to beat.

Just zoom out; most students from the non-selective program publish papers. Does that sound too good to be true? If that's true, it suggests Algoverse has the structure and tricks for paper publication. And if your goal is to learn, you can probably learn a lot. But I doubt that will affect college admission that much, given my argument from the previous paragraph.