That has sort of been my take on it as well.

I have a SPA and have 'converted' it into a PWA. My motivation for that largely has been to better control the way assets are cached on the client, I can now control better with the service worker, but there is one really nice benefit:

With the PWA, android devices (hopefully iPhone soon too) can 'install' the PWA to the device without going through Google Play Store (in fact, you can have the PWA install the android app available on Play Store instead, if you prefer). This makes the web-page appear to the user as an app, with a nice icon, and snappy performance relative to opening a link in chrome (even though it is a chrome instance running the 'installed PWA')