The thing is, what makes an app native? The kernel running on all of these devices is Linux. It's just different layers in userspace that define whether these apps are native or not. If Google decide they are going to design and build a userspace layer for Chrome OS that is capable of running web apps, Android apps, Qt apps and GTK apps, what's to say that none of those apps aren't running natively or can't work perfectly?

Likewise if Jolla wants an Android layer to be part of Sailfish, what's to say it's not native? There's certainly no software emulation at play here. The quality of that layer compared to your usual Android devices is not related to whether it's native or not. Jolla has limited resources. It just another software problem that's in the process of being solved.