This blend of highly dismissive comments on expertise and the volume of work it takes to achieve it is starting to become a cliche in software development circles, similar in tone to the denigrating comments regarding roles such as system architects.
Expertise is domain knowledge supported with real world experience. It's not fancy slideshows.
The video compression specialist outperforms you in every way because he's been studying the problem domain, researching the problem, implementing solutions, and analysing the results. And meanwhile you barely know what's a ffmpeg.
Some developers think too highly of themselves to the point they feel they can parachute into a problem and talk down anyone around them, including experts and specialists. And this shows in the code, and unfortunately in team dynamics.