These are totally different scenarios.

The lock on my front door only has to be strong enough to stop whoever wants to physically approach my house and attempt to pick it. The lock on my home network needs to be strong enough to stop anyone in the world from attempting to hack it.

> There's always going to be a way for malicious people to do harm.

This is an example of statement, that while technically true, is so useless it might as well not be. It would be like saying that humans have been killing each other since before nuclear weapons existed, so there is no reason to worry about multi megaton thermonuclear warheads. They are different levels of risk by orders of magnitude.

When you’re connected to the internet the number of adversaries willing to try goes up by probably 6 orders of magnitude. Not only that, many of them will be living in a regime where there is no possible way for them to get punished by doing it to you.

Ransomware brought significant amounts of income to the North Korean government.

These are not extreme hypotheticals. They’ve shut down fucking hospitals to shake down people for money. Once the opportunity is great enough, they’ll have no qualms stopping people’s cars from starting to ask for a little crypto currency.