And this is after having already abandoned Wallabag, an open-source read-it-later service I had been using for about a month; I eventually found that the inconvenience (of having an iOS app that does not preserve my place in an article; of having to re-login frequently on the web; of the lack of integration with other services) outweighed any ideological reasons I had for hosting my data on my own server. So I'm back with Instapaper, which is what I had been using for years.
After much frustration with using an open-source alternative and trying to code my own, I am realizing that I don't have to reinvent the wheel if I am happy with how the current one rolls. My feelings about Instapaper having a database of all my saved articles are changing. Instapaper isn't creepy like Google; I just have preferred to not have my data hosted elsewhere. But Instapaper is such a good product that I'm willing to make the tradeoff. Betaworks (Instapaper's new owner) is not using my data to tailor ads to me; they're just performing a service for which I paid a few dollars to Marco Arment many years ago.