Confirmed. On my Android (Samsung) it’s just a link. When I did it on an iPhone (iPhone 6 in fact), it was a proper PWA. Not sure why it works as a PWA only on iPhone but not on Android.

I tried to run Lighthouse through Chrome dev tools on kbin.social but it seems like CloudFlare is throwing that off.
Lighthouse reports that fedia.io isn’t PWA compliant due to a single issue in the manifest file (probably forgot to update a url from kbin to fedia or something trivial like that).

Edit: and a day later, with CloudFlare off, I get the install option and the true PWA.