Android browsers can already add pages to home screen but Hermit takes this even futher.
It has significantly better UX with frameless and full screen modes. You can bookmark pages, so on Lemmy you can quickly bookmark community in specific sorting order. There are user scripts and blockers and loads of customization. You can even add push notifications for changes on the site or RSS feed.
I’ve been running most Fediverse web apps through Hermit and it works really well! The only exception is that I couldn’t figure out how to setup notifications on Mastodon.
I don’t really see how this adds a whole lot except for removing the frames of the browser app. But in exchange you lose the ability to use addons and their corresponding scripts & styles, while all the extra features are paywalled.
For lemmy, not a huge benefit, but for other less trustworthy social apps, you can run them sandboxed so they can’t track your other activity. Though Firefox also sandboxes cookies now too. But hermit has some other nice features regarding bookmarking, user scripts, etc
Unfortunately browser apps are really buggy and never really cared for by neither Chrome or Firefox. So, it’s always like using a beta feature that sometimes works compared to Hermit which is quite polished.