In my regular RSS reader I often have the problem that some feeds are not full feeds, or some images are missing (In case they have some gallery) and I have to click out to the page, even just to verify I got the full text. That always kinda stops me from going the eink route where I don’t have a proper browser.
Depends on which feeds you subscribe to I guess, probably works really well for long form, reliable feeds.
One way to get around this in some cases is to subscribe to the feed's associated email newsletter, which, IME, is more likely to have the full text of the article. This, of course, introduces other problems[1], but if your goal is to remove reasons to habitually look at your phone, it's worth investigating.
[1] The feed needs to have a newsletter in the first place, you probably need to clean up the markdown a bit before shoving it into an epub (I've noticed that table-based layouts are much more common, for instance), and your email provider probably doesn't provide an RSS feed of your inbox. The latter two are straightforward to fix but do require a bit of programming elbow grease.
The really annoying ones are substack as it often wants you to sign in to access even free full text posts.
A majority of the feeds I subscribe to do not include the full text in the feed themselves which is one of the main reasons I use Miniflux which has an option to fetch the full article text and works very reliably. Of the more than 150 feeds I am subscribed to, I think there are fewer than 5 that Miniflux is unable to fetch the text for. Miniflux can also connect to Wallabag to quickly save pages to it using the full text. That is great because Wallabag is often unable to fetch text directly on its own.