I don't think any toilet built here in Finland since at least the 50's (some of those still exist, earlier I'm not sure of) have needed a plunger either, those things just work. The US plunger thing just baffles me. And banking too, sure.
Why wouldn't these be the default in all new construction everywhere? Are there downsides?
Not that I'm aware of. Lived in NZ for 5 years and just moved into a brand new construction in CA just a few months back. Terrible. I've had to plunge(technically I use the scrubber to generate the pressure) a few times already :(
Also, the showers mostly all have baskets under the drain caps to capture hair and stuff now.
I've literally never owned a plunger in my whole life, and I don't know anybody who does. It baffles me everything I'm in the US and every toilet has a plunger!