Keeping in mind that this is a machine run test, you must take the results with a grain of salt.
I'm looking at this from an seo perspective, I agree that Nodebb is "zippy" but if Google are going to be using this tool (or something similar) to rank Nodebb forums, then the results are highly relevant.
What's the point in having a cool looking forum with no members or visitors?
NodeBB is quite zippy on my phone
It's also zippy on my iPhone & iPad and my daughters Android tablet and Windows phone.