>The site has received almost no technical improvements,
Not true. Theyre under the surface or not webfacing. (Like Kindle integration)
The biggest technical issue with Goodreads is this: the site was originally built as a giant pile of Rails spaghetti with views mixed with business logic and such and then a fuck ton of weird features built and left to sit there. Like way WAY more than you'd think unless you actively hunted through the webmap.
There is an ongoing metaproject to detangle the spaghetti into an api that sits in front of the databases and deprecate the Rails hell pit (derisively called 'the monolith' internally). It's taken years. It is still in progress. It was started far too late in the game. When people talk about tech debt at Goodreads thats mainly what they mean.