All LCD technologies have pixel transition times that vary based on the old and new colors and are often larger than the refresh rate, this is nothing new with OLED. Typically these do get improved over time. I've compared the video on my OLED phone and non-OLED monitor and the smearing is not significantly different.

That's only relevant for animations.

Including scrolling, which is an extremely common interaction. I still stick with pure black whenever possible though, despite that.

That and doom scrolling on on my pure black theme'd apps at night. Although I've gotten used to the smearing and don't really mind it anymore.