This is a strange argument, kind of like, "We can't defund the police, because look at all of the crime out there!" If there's so much crime occuring already, then what in the world are the police doing?
To an extent, crime can't be eliminated. You can't even eliminate crime by instituting a strict authoritarian regime, because power corrupts, and those in power become criminals themselves. That's why turning big tech companies into paternalistic device authoritarians doesn't work. The big tech companies have become massively corrupt, demanding a 30% cut of everything that happens on your devices, in return for what? Some low paid, low skill reviewer spending a few minutes to approve or reject a third party app submission? That's not security, it's security theater.
There were phone scams before there were smartphones. Before there were mobile phones, when everyone had a landline. There's no technical solution for crime and scams, much as tech people want there to be. Education and viligence have always been the only effective resistance. Unfortunately, the big tech companies don't want to do education; to the contrary, they want consumers to be eternally technically ignorant—despite the increasing importance of computers in our lives—because that's more profitable. At least with cars, we have mandatory driver's education.