That’s not my approach, I’ve always allowed my children to play with my iPhone since they were toddlers. There have been times like sitting in A&E or when we’ve been at places where they are in a pushchair and needed to be entertained and I’ve often pacified them with my iPhone with YouTube for kids or something on Netflix. I wouldn’t have been able to do that without a case on the iPhone though which for me is an added benefit of protecting the device along with making it nicer to use.
We all raise our kids differently.
I will just say that I was raised by two people from the Silent Generation, born 1935 and 1941. They waited until 1970 to have me and my sister was 1972. So, my dad was 35 when I was born. My point here is that I got the Silent Generation values about children: seen and not heard, speak only when spoken to by an adult.
I did NOT pass that on, but there were certain other values I passed on. Both my wife and I are Gen-X and latchkey kids. We both learned to entertain ourselves and fend for ourselves when alone. And the stuff about respecting other peoples property that I got from my parents got passed on too.
This is not to say that my kids did not have toys. They had backpacks as little kids and they chose the toys the wanted to bring. Later, some of that stuff was electronic game/learning devices. Stuff built in hard plastic.
But they did not get our phones to play with. Those aren't toys and were ours. When they DID get old enough, I allowed them use at home of an iPhone 3GS. That was some time in 2013 I think. My daughter would have been five then. When my son was five he got an iBook G3 with a broken airport antenna. He had to use it connected to an ethernet cable. That was solely his and he took care of it.
My son was 15 (2018) when he got his first real phone, an 8GB iPhone 4s with a 2GB data cap. We needed to get a hold of him when he was outside the house (at school) because he was responsible for his sister who attended the same schools he did.
Eventually, we allowed our daughter to take the 3GS out with her. It worked only on WiFi. But she was older then. I allowed her to use my iPad (Air 2). She dented it. That was the last time she was allowed to use my iPads.
One of the things we did pass on from my parents was no devices at the table. Or rather, they can be at the table, but you can't be using them. My son was going to throw up once and this was the ONE time I handed him my phone - to distract him. It worked, I got my phone back and he reengaged in the conversation, My mother approved (she was there at the time).
This has changed over time. Now we bring our devices to the table, but they are used solely to look up facts or support a point in discussion. We aren't on them ignoring each other.
Now both kids have their own phones. But they use them for the intended purpose. They have plenty of other things/hobbies to engage in.