I personally know many stupid people who still preferred 5th gen city over Yaris. I'm no fan of Yaris, but it's still a better car than the 5th gen city. Plus atlas loves underproduction. It's undeniable city's sales took a huge hit since it got competition. Before it was the cheapest brand new sedan and that is why it had huge demand. There is no way atlas would've bothered with 6th gen if 5th gen got no competition. Yaris has forced their hand, it's undeniable.
You can see city's history as proof. It was always priced close to the corolla 1.3 but it always had something special going on for it. 3rd gen was basically a cut price civic. 4th gen had insane fuel economy. 5th gen had better fuel economy and performance than corolla 1.3, but was worse in all other categories and was priced similar to 10th gen corolla. That's why 5th gen had lower sales till 11th gen corolla came with a much higher price. City became the default cheap sedan after and only became a huge hit after 2015. They simply couldn't survive now with all the competition.
I still believe the 6th gen city would be the best sedan, in 1.5 variants at least, if priced similar to Yaris. But there's no way it'll have the same level of success as the 5th gen enjoyed for the past 6 years.