As far as I'm aware, kids at that age are very dependent on experiencing the effects of their actions. They lift the wooden cube and drop it, and it makes a sound and rolls a bit. Do it again and it does it similarly but different. Push this chair leg and the whole chair moves away, pull it and the whole chair moves back. This builds their world understanding but also motor skills and reflexes.

Now they did not specify in the freely accessible portion but especially non-interactive stimulus is thus problematic as I understand.

As I recall there have been studies on this regarding toys that flashes lights and makes sound without interaction causing it, and the babies have a markedly different brain response to those, compared to toys which only blinks and sounds in response to direct interaction.

The other reason is that simply playing with the baby using wooden blocks, small dolls and such toys is in my experience plenty to keep them engaged.

A buddies toddler is about a year and just managed to place two cubes on top of each other without toppling them, and was is excited he cries with joy each time he does it. That's learning motor skills and experiencing reward you don't get with at least passive screen use.