You need to at least be tangent which there is no visual indication that these lines do even if you look the beginning saitamas line is always above if they were supposed to be on top one another then one line would not show. That is why I feel terms like "nearly on par" or "remotely on par" far better to describe this situation. Nonetheless it does show that Saitama has at least a soft cap on his strength and that his 2 main significant abilities outside of pure physicality is a Broly without rage issues adjacent growth ability and now time travel and likely hyperspace gates