And you think the emulator actually takes the place of real live hardware, the quirks , the performance, etc?
depends on the complexity of the app. An app that can reasonably be a PWA (e.g. it is more or less a webpage wrapped in an APK) can probably be tested well enough on a dozen emulator pofiles and a few physical devices you have lying around.
And those are the very apps that are going to run worse on low end devices with poor rendering performance…