True. I was replying to a sarcastic comment in a sarcastic way. Mea culpa.
> Removing an advanced library
They made it clear they didn't remove the library. They still load it later, and still use it.
> from a simple project
They make it clear it's not a simple project. In fact, it's probably one of the more complex pieces of the project.
> increases performance.
No, it increased specific metrics that they cared about.
> Sorry for being sarcastic but don't you also find this too obvious?
Your comment, or their results? Your comment is incorrect based on a single slide and taken out of context. As for the actual reasons, no, they are not obvious at all. Incredibly intelligent people didn't find it obvious, as this was something they clearly didn't see at the beginning, and instead relied on measurements.