That’s a parenting red flag. That happens because the parents keep putting a phone in the kid’s hand and expect the phone to occupy all their time. Spend time reading and speaking to the kid in his mother tongue rather than giving them a phone and they’ll become proficient pretty quickly.
This is a parenting issue, not a kid thing. It’s because parents put a tablet in their kid’s hands, teach the kid to use it, then expect the tablet to occupy all the kid’s time while they don’t engage with the kid.
I have a 5 yo and a 3 yo. We have a family iPad, but the kids barely know how to use it. They virtually never watch videos on it (only exception was the one time they’ve been on an airplane). My 5 yo is very artistically inclined, so we downloaded a sketchpad app she can draw with. She also builds legos, so we downloaded the lego app she can use for instructions. Those are the only apps she knows how to use, and she doesn’t even know how to navigate to find them. We have to open the app for her and get her setup before she can run with it. My 3 yo doesn’t even know how to do that much.
We mostly use the iPad to video chat family or play music, both of which are controlled by grown ups.
Yet my kids are extremely proficient at a lot of other stuff relative to kids their own age. The 5 yo can fully read and write and can do simple arithmetic. The 3 yo can read small words, can write all her letters, and can count at least to 100. They both do small chores around the house, both help cook (especially the 3 yo has gotten very good at slicing veggies).
Toddlers being hypercompetent with a tablet is 100% a parenting red flag. It shows the parents aren’t very engaged and just let the tablet do all the parenting for them.
Toddlers have object permanence. Object permanence develops at around 4-6 months old. Kids are still infants at that point. Toddlers are generally 1-3 years old.