> This seems like a fun side project idea honestly - can I ask what’s most broken and which great features are missing?
It's basically just the momentum it has, alongside with crowdfunded book directory (you don't have to enter the metadata manually in like 99.999% of the cases). I'm not gonna say "don't bother", but I've personally used three Goodreads alternatives over the years and nobody mentioned a single one of them yet. I've settled on BookDigits[0], which is what Goodreads should be if you ask me.
> Yes, Amazon could shut it down but eh, might be worth the risk
Technically API isn't the only way users could extract their data from Goodreads. There's also export/import tool that exports data in CSV, and there's also RSS feed that you could ask for.
If there's one good thing I can say about Goodreads, it's that it's not a walled garden.