What’s the problem openings books? Basically that they’re all pretty much wrong about everything!
It’s not the fault of the authors, it’s more the culture of ‘theory’ that has arisen and the story line that the best moves are there and the route to excellence is to discover and then repeat them. The authors simply serve this false idea which is what is required of them by the chess playing public.
The game below is a good example as it has been used as a model example of White’s play against the Steinitz Variation of the Spanish, and by several different books. One book that I have mentions 33.Rc1 as an improvement for White, but haven’t we gone rather far? And how inconvenient it would be to find improvements for BLACK rather than White when what we really want to do is show a safe and simple edge for White!
So does Black have improvements in this line? Maybe! Of course I wouldn’t want to spoil it for you by indicating what they are, though I can say that if someone doesn’t play any bad moves they won’t end up with a poor position…