I don't have time to read the entire paper but I would like to share an anecdote. I worked at a company with a well staffed/funded machine learning team. They were in charge of recommendation systems - think along the lines of youtube up next videos. My team wanted better recommendations (really, less editorial intensive) so the ML team spent weeks crafting 12 or more variants of their recommendation system for our c…
up next recommendations wont work without advanced image recognition and topics gathering - basically titles/tags for most videos are garbage and clickbait, and most of youtube work by watching buzzed videos: some well known (by a big amout of watchers) "influencers" push video of some topic (thing/brand) then it get traction from other content creators - they produce videos about it and watchers tend to stick to buzzed topics. it's like news about news.
if your team used ml to recommend up next on your own video hosting your result simply means your videos are equally not on topic Or non-interesting for your service auditory; or they are garbage.