Sorry, I just realized that question was poorly stated. It misses an important point: there has to be a decently sized catalog. It doesn't need to rival Libgen, but it should be something that covers most of your bases. Sorry for kinda moving the goalposts here, but right now, most of the time, looking for a particular book you can't get your hands on it DRM free without going to Libgen. That's the thing which has to change.