Apparently it was created internally for MrBeast and they then decided to release it for public use as well.

https://twitter.com/MrBeast/status/1735360557711065234

Socialblade lost access to most of the data they used. Unclear how this improves on that

Pretty sure socialblade is unmaintained, if the state of their blog is of any indication. There's been no updates there since 2020, with the last subject relating to COPPA enforcement on YouTube.

Given that specific subject did have a few follow-ups with no relevant notes published, my guess is that the site is mostly in maintenance mode/runs until it breaks with no active features being developed.

This was previously an internal tool built by the MrBeast team that they decided to open to the public