It's not an issue of permission, it's an issue of trying to make a computer that's safe for grandma to use. Criminals can and will convince grandma to navigate a byzantine labyrinth of prompts and technical measures in order to drain her bank account. That's the threat model we're dealing with here.
People also forget that it makes it safe for people who aren't grandmas. The reason why you think it's just grandmas is because, for you to get a virus or your computer hacked now, it requires so many user gaffes for something like that to happen. In addition, it almost always involves typing in or telling someone your password when you shouldn’t. In the early 2000s, I still remember there was some ad affiliate for the cyanide and happiness webcomic website that, if you let it's ad load, instantly infected your computer with adware just from visiting the site. That’s unheard of now because of increasingly protective/restrictive policies set by technology companies. It’s one of those situations where if a system is working correctly, you won’t even know it’s working at all.
I helped my mother out with a computer, gave her a mac after she called twic a wee about a windows popup. Eventually she became a grandmother, and later in old age, with dementia she stlll using the mac more or less successfully to google and e-mail.
Intentionality, coordination are important for keeping cognitive faculty.
It all sounds so easy, but letting her send e-mail through voice could create confusing situations.
