That's not true.
Being limited in what you can do with your properties is never a blessing.
Hammers are dangerous yet they are sold in supermarkets.
Hell, in US even guns are sold in supermarkets so that kids can kill other kids at school and nobody stops them and we are arguing about installing apps on a phone?
Apple could make it clear that it's risky and that would be it.
The rhetoric of the "old parents that can't help themselves" is wrong and most of all agist.
There's no risk of them installing dodgy apps, because they usually don't install new apps.
My mom doesn't even know how to change time on her phone but she's smart enough to not break what's working.
I installed WhatsApp on her phone and that's all she needed, there's no way she could install something bad by chance and she's on Android, according to the Apple fanboys she should be running around with a virus bomb in her purse.
Guess what?
She's completely fine.
Another important point is that Apple is not competing with Android, Apple is competing with other smartphone producers.
Apple is a monopolyst because it locks users in, you can't change OS on your phone, you can't install iOs on other brands, you can't move your apps and data from iOs to Android, while the contrary is pretty straightforward.
You can't even use the web freely, because alternative browsers are forbidden on Apple Store.
Apple is not competing in a free market, Apple is making impossible to switch to competitors and thanks to this lock they can charge any amount they want.
I'm old enough to remember MS being bashed for proposing the TwC (trustworthy computing) in 2002 and now I have to watch people kneeling in front of the richest company around just because they don't want to help their parents?
That must be a new low for our society.