The correlations are 0.25-0.5, which is quite poor (Gaussian distribution plots with those correlations look like noise). That's before analyzing the methodology and assumptions.
For example, in difficult perceptual tasks ("can you taste which of these three biscuits is different" [one biscuit is made with slightly less sugar]), a correlation of 0.3 is commonplace and considered an appropriate amount of annotator agreement to make decisions.
Not here though, where you are trying to prove a (near) equivalence.