Smartphones and the internet are really useful and convenient. Even if we could make it work, it seems quite rude to say that people should be excluded from it because we can't be bothered to make it safe.

Consider an older technology that became fundamental to much of daily life a century or two ago: writing. After a few millennia where literacy was a specialized skill, we pretty quickly transitioned to a society where it was essential for common activities. Rather than make sure everything had pictures and such to accommodate the illiterate, we tried to make it so that the entire population is literate, and came pretty close to succeeding. There are people who just outright can't read for whatever reason, but they're a very small minority and we aim to accommodate them by giving them assistance so they can get by in a literate world, rather than changing the world so you don't need to be able to read to live a normal life.

Rather than saying that half the population (a low estimate, I believe, for how many people will fall prey to malware in an anything-goes world) should abandon this technology, we should work to make it so they don't have to, with some combination of education and technological measures.

Some people don't want to be taught about some things because they don't care enough about them. I was told a story as a kid about a grandma that didn't want to learn to read and write. It's the same thing here — there are people who don't want a smartphone. They were just fine with an old cell phone that could only call and text, but then the society forced them to buy a smartphone, so they did, but they still don't really want it. It's still a burden to them. It still creates more problems for them than it solves. I know several people like that.