Lasker says that a master using his method could educate a beginner to the level where 'if afforded any odds would surely be the victor'.
Modern Lasker/Capablanca

What would be the modern equivalent of Lasker's Manual of Chess, Capablanca's Chess Fundamentals, Tarrasch's Game of Chess, Staunton's Handbook etc?
i.e a one-volume manual to take the beginner/novice to expert level. Capa thought that his book contained 'everything you need, nothing to be added and nothing to be changed'. Does that still hold? Is it just a marketing ploy that chess efficiency seems to require endless years and multiple books/means of learning, or did Lasker have it right at his 200 hours (10 on openings!?)
What did Lasker mean by expert level. I have read Lasker's book and Capablanca's book. They did not have a defined definition back then what a expert level means.
Some argue today that Morphy, Staunton, Blackburn, Steinitz... were only expert level themselves.
that last sentence is quite a stretch. what morphy could do tactically i expect from an IM that would be known to be a tactician. even Staunton i would put at least 200 points above expert. these players made sense. They didnt know the latest opening theory and didnt have every positional idea masticated by literature, but they could fight.
I have played old out of prime FM's that were once borderline IM's that play harmless opening variations and lots of silent rook pawn moves, but their positional understanding is so high, it was only a matter of time they pounced on a mistake i would play. They gave me advantage ...until i didn't have it. There were simply better players. IT would take a higher player than me before those small mistakes they did would amount to something.
so this idea that these old masters would be hopeless the weaker masters of today to me absurd. You will come prepped to the teeth, they will come out with an old steinitz or a cambridge springs defense or some other opening pepperidge farms remembers, be slightly worse for a little longer and then outplay you.

Indeed darkunorthodox88. It's often said that the 'fundamentals' of chess haven't really changed since Steinitz first set them out. Another reason why Capa claimed his book would be as good in 100 years time, and indeed as long as chess rules remained the same. Maybe Botvinnik was right in thinking it the greatest chess book ever written.

Jacob has certainly written a lot of books rivuchess (and he's now Scottish!), but I can't think any of them to be the one-volume all encompassing work I'm thinking of.

The Soviet Chess Primer by Ilya Maizelis.....fits the OP's criteria...
I comment on the book here (search 'soviet')...
Good Chess Books for Beginners and Beyond...
https://www.chess.com/blog/RussBell/good-chess-books-for-beginners-and-beyond
https://www.chess.com/blog/RussBell
Tarrasch's The Game of Chess would also be a good choice. I comment on it as well. Note there is an Algebraic edition.
What would be the modern equivalent of Lasker's Manual of Chess, Capablanca's Chess Fundamentals, Tarrasch's Game of Chess, Staunton's Handbook etc?
i.e a one-volume manual to take the beginner/novice to expert level. Capa thought that his book contained 'everything you need, nothing to be added and nothing to be changed'. Does that still hold? Is it just a marketing ploy that chess efficiency seems to require endless years and multiple books/means of learning, or did Lasker have it right at his 200 hours (10 on openings!?)