YouTube is the original TikTok. Back in the day, there used to be a limited video length. The recommendation algorithm has always been very good, but for privacy perception reasons Google added a configurable limited time window for history used for recommendations. With shorts, that time window might as well be infinite in comparison, and Google can ramp up the algorithmic exploitation to the max.<p>Fortunately YouTube does have various means to control your experience like subscriptions and RSS feeds, and videos of greater substance do exist. I use a Desktop Firefox addon that blocks shorts, as I generally perceive them to be low quality.
Custom designed and tested to be as effective as humanly possible. They know all the buttons to push, and how to push them the most effectively. It's good that you were able to recognize it and stop, but so many more people don't or can't.
I find the promoted YT shorts annoying. It's non-stop boobs and butts and I have never searched for this on YT. There is uBlock code to filter out those promoted videos but it sometimes breaks the site.