From what I’ve gathered from various big time 'tubers I’ve watched for years now, as they slowly trickle tidbits of info about what it’s like working as a YouTuber, and what tools and tips Google gives them to assist: Google/YouTube is the one that recommended using the types of thumbnails commonly employed by uploaders, along with a ton of other things that are ubequitous to the platform (such as the phrase “like, subscribe and ring that bell!”).
YouTube also decided that every video should be ten minutes long and made the algorithm recommend videos of that length so everyone had to start making their videos ten minutes long even if it made no sense to do so.
From what I’ve gathered from various big time 'tubers I’ve watched for years now, as they slowly trickle tidbits of info about what it’s like working as a YouTuber, and what tools and tips Google gives them to assist: Google/YouTube is the one that recommended using the types of thumbnails commonly employed by uploaders, along with a ton of other things that are ubequitous to the platform (such as the phrase “like, subscribe and ring that bell!”).
YouTube also decided that every video should be ten minutes long and made the algorithm recommend videos of that length so everyone had to start making their videos ten minutes long even if it made no sense to do so.