Sorry, in my national market. Apple has 51%, Samsung has around 28% and Google 5%. These 3 hold almost 85% of the UK market.
Samsung, from what I remember used to side-load tons of apps (some alongside identical stock Android apps), so it's in their best interest to maximise screen time through media apps, which generally work best on a bigger screen.
It's against all of these companies interests to sell you a phone which you quickly use and put away. They all have every incentive to keep you staring, because they're all getting extra money from every ad you see in a game, TV show, movie, web browsing, or wherever else they can slot it.
Globally, Apple has what 20% market share? And besides Qualcomm chips, Apple has a complete separate parts supply chain than Android.
Besides, Samsung could definitely create its own small phone and would if there were a market.