So this is a US thing, with the weird half-full-of-water bowls, right?
I've had a messy clog maybe once in my life, but evven then it didn't just fill horrifically with water and overflow. It's such a trope that all I can assume is that maybe US toilets do that sometimes?
American plumbing sucks. I never once clogged a toilet in my 10 years living in Germany - those things would suck down ANYTHING. Here they sometimes just decide to back up for no visible reason.
But like the other poster said, they rarely overflow - you just have a gross bowl of water to deal with trying to plunge it down.
It happens occasionally, it's not like they overflow after one flush. You flush, notice the water isn't going down, plunger it, and usually you're good